CC2420DK

CC2420 TI | Alldatasheet

Document overview

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Technical content

2.4 GHz IEEE 802.15.4 / ZigBee-ready RF Transceiver

Applications

• 2.4 GHz IEEE 802.15.4 systems
• ZigBee systems
• Home/building automation
• Industrial Control
• Wireless sensor networks
• PC peripherals
• Consumer Electronics Product Description The CC2420 is a true single-chip 2.4 GHz IEEE 802.15.4 compliant RF transceiver designed for low power and low voltage wireless applications. CC2420 includes a digital direct sequence spread spectrum baseband modem providing a spreading gain of 9 dB and an effective data rate of 250 kbps. The CC2420 is a low-cost, highly integrated solution for robust wireless communication in the 2.4 GHz unlicensed ISM band. It complies with worldwide regulations covered by ETSI EN 300 328 and EN 300 440 class 2 (Europe), FCC CFR47 Part 15 (US) and ARIB STD-T66 (Japan). The CC2420 provides extensive hardware support for packet handling, data buffering, burst transmissions, data encryption, data aut hentication, clear channel assessment, link quality indication and packet timing information. These features reduce the load on the host controller and allow CC2420 to interface low-cost microcontrollers. The configuration interface and transmit / receive FIFOs of CC2420 are accessed via an SPI interface. In a typical application CC2420 will be used together with a microcontroller and a few external passive components. CC2420 is based on Chipcon’s SmartRF ®- 03 technology in 0.18 µm CMOS. Key Features
• True single-chip 2.4 GHz IEEE 802.15.4 compliant RF transceiver with baseband modem and MAC support
• DSSS baseband modem with 2 MChips/s and 250 kbps effective data rate.
• Suitable for both RFD and FFD operation
• Low current consumption (RX: 18.8 mA, TX: 17.4 mA)
• Low supply voltage (2.1 – 3.6 V) with integrated voltage regulator
• Low supply voltage (1.6 – 2.0 V) with external voltage regulator
• Programmable output power
• No external RF switch / filter needed
• I/Q low-IF receiver
• I/Q direct upconversion transmitter
• Very few external components
• 128(RX) + 128(TX) byte data buffering
• Digital RSSI / LQI support
• Hardware MAC encryption (AES-128)
• Battery monitor
• QLP-48 package, 7x7 mm
• Complies with ETSI EN 300 328, EN 300 440 class 2, FCC CFR-47 part 15 and ARIB STD-T66
• Powerful and flexible development tools available

1 Abbreviations

ADC - Analog to Digital Converter AES - Advanced Encryption Standard AGC - Automatic Gain Control ARIB - Association of Radio Industries and Businesses BER - Bit Error Rate CBC-MAC - Cipher Block Chaini ng Message Authentication Code CCA - Clear Channel Assessment CCM - Counter mode + CBC-MAC CFR - Code of Federal Regulations CSMA-CA - Carrier Sense Multiple Access with Collision Avoidance CTR - Counter mode (encryption) CW - Continuous Wave DAC - Digital to Analog Converter DSSS - Direct Sequence Spread Spectrum ESD - Electro Static Discharge ESR - Equivalent Series Resistance EVM - Error Vector Magnitude FCC - Federal Communications Commission FCF - Frame Control Field FIFO - First In First Out FFCTRL - FIFO and Frame Control HSSD - High Speed Serial Debug IEEE - Institute of Electrical and Electronics Engineers IF - Intermediate Frequency ISM - Industrial, Scientific and Medical ITU-T - International Telecommunication Union – Telecommunication Standardization Sector I/O - Input / Output I/Q - In-phase / Quadrature-phase kbps - kilo bits per second LNA - Low-Noise Amplifier LO - Local Oscillator LQI - Link Quality Indication LSB - Least Significant Bit / Byte MAC - Medium Access Control MFR - MAC Footer MHR - MAC Header MIC - Message Integrity Code MPDU - MAC Protocol Data Unit MSDU - MAC Service Data Unit NA - Not Available NC - Not Connected O-QPSK - Offset - Quadrature Phase Shift Keying PA - Power Amplifier PCB - Printed Circuit Board PER - Packet Error Rate PHY - Physical Layer PHR - PHY Header PLL - Phase Locked Loop PSDU - PHY Service Data Unit QLP - Quad Leadless Package RAM - Random Access Memory RBW - Resolution BandWidth RF - Radio Frequency RSSI - Receive Signal Strength Indicator RX - Receive

SHR - Synchronisation Header SPI - Serial Peripheral Interface TBD - To Be Decided / To Be Defined T/R - Transmit / Receive TX - Transmit VCO - Voltage Controlled Oscillator VGA - Variable Gain Amplifier

2 References

[1] IEEE std. 802.15.4 - 2003: Wirele ss Medium Access Control (MAC) and Physical Layer (PHY) specifications for Low Rate Wireless Personal Area Networks (LR-WPANs) [2] NIST FIPS Pub 197: Advanced Encryption Standard (AES), Federal Information Processing Standards P ublication 197, US Department of http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf [3] R. Housley, D. Whiting, N. Fe rguson, Counter with CBC-MAC (CCM), submitted to NIST, June 3, 2002. Available from the NIST website. http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/ProposedModesPa ge.html

3 Features

• 2400 – 2483.5 MHz RF Transceiver
• Direct Sequence Spread Spectrum (DSSS) transceiver
• 250 kbps data rate, 2 MChip/s chip rate
• O-QPSK with half sine pulse shaping modulation
• Very low current consumption (RX: 18.8 mA, TX: 17.4 mA)
• High sensitivity (-95 dBm)
• High adjacent channel rejection (30/45 dB)
• High alternate channel rejection (53/54 dB)
• On-chip VCO, LNA and PA
• Low supply voltage (2.1 – 3.6 V) with on-chip voltage regulator
• Programmable output power
• I/Q low-IF soft decision receiver
• I/Q direct up-conversion transmitter
• Separate transmit and receive FIFOs
• 128 byte transmit data FIFO
• 128 byte receive data FIFO
• Very few external components
• Only reference crystal and a minimised number of passives
• No external filters needed
• Easy configuration interface
• 4-wire SPI interface
• Serial clock up to 10 MHz
• 802.15.4 MAC hardware support:
• Automatic preamble generator
• Synchronisation word insertion/detection
• CRC-16 computation and checking over the MAC payload
• Clear Channel Assessment
• Energy detection / digital RSSI
• Link Quality Indication
• Full automatic MAC security (CTR, CBC-MAC, CCM)
• 802.15.4 MAC hardware security:
• Automated security operations within the receive and transmit FIFOs.
• CTR mode encryption / decryption
• CBC-MAC authentication
• CCM encryption / decryption and authentication
• Stand-alone AES encryption
• Development tools available
• Fully equipped development kit
• Demonstration board reference design with microcontroller code Easy-to-use software for generating the CC2420 configu- ration data
• Small size QLP-48 package, 7 x 7 mm
• Complies with EN 300 328, EN 300 440 class 2, FCC CFR47 part 15 and ARIB STD-T66

4 Absolute Maximum Ratings

Parameter Min. Max. Units Condition Supply voltage for on-chip voltage regulator, VREG_IN pin 43. -0.3 3.6 V Supply voltage (VDDIO) for digital I/Os, DVDD3.3, pin 25. -0.3 3.6 V Supply voltage (VDD) on AVDD_VCO, DVDD1.8, etc (pin no 1, 2, 3, 4, 10, 14, 15, 17, 18, 20, 26, 35, 37, 44 and 48) −0.3 2.0 V Voltage on any digital I/O pin, (pin no. 21, 27-34 and 41) -0.3 VDDIO+0.3, max 3.6 V Voltage on any other pin, (pin no. 6, 7, 8, 11, 12, 13, 16, 36, 38, 39, 40, 45, 46 and 47) -0.3 VDD+0.3, max 2.0 V Input RF level 10 dBm Storage temperature range −50 150 °C Reflow solder temperature 260 °C T = 10 s The absolute maximum ratings given above should under no circumstances be violated. Stress exceeding one or more of the limiting values may cause permanent damage to the device. Caution! ESD sensitive device. Precaution should be used when handling the device in order to prevent permanent damage.

5 Operating Conditions

Parameter Min. Typ. Max. Units Condition Supply voltage for on-chip voltage regulator, VREG_IN pin 43. 2.1 3.6 V Supply voltage (VDDIO) for digital I/Os, DVDD3.3, pin 25 . 1.6 3.6 V The digital I/O voltage ( DVDD3.3 pin) must match the external interfacing circuit (e.g. microcontroller). Supply voltage (VDD) on AVDD_VCO, DVDD1.8, etc (pin no 1, 2, 3, 4, 10, 14, 15, 17, 18, 20, 26, 35, 37, 44 and 48) 1.6 1.8 2.0 V The typical application uses regulated

1.8 V supply generated by the on-chip

voltage regulator. Operating ambient temperature range, TA −40 85 °C

6 Electrical Specifications

Measured on CC2420 EM with transmission line balun, T A = 25 °C, DVDD3.3 and VREG_IN = 3.3 V, internal voltage regulator used if nothing else stated.

6.1 Overall

Parameter Min. Typ. Max. Unit Condition / Note RF Frequency Range 2400 2483.5 MHz Programmable in 1 MHz steps, 5 MHz steps for compliance with [1]

6.2 Transmit Section

Parameter Min. Typ. Max. Unit Condition / Note Transmit bit rate 250 250 kbps As defined by [1] Transmit chip rate 2000 2000 kChips/s As defined by [1] Nominal output power -3 0 dBm Delivered to a single ended 50 Ω load through a balun. [1] requires minimum –3 dBm Programmable output power range 24 dB The output power is programmable in 8 steps from approximately –24 to 0 dBm. Harmonics nd harmonic rd harmonic -44 -64 dBm dBm Measured conducted with 1 MHz resolution bandwidth on spectrum analyser. At max output power delivered to a single ended 50 Ω load through a balun. See page 54. Spurious emission 30 - 1000 MHz 1– 12.75 GHz 1.8 – 1.9 GHz 5.15 – 5.3 GHz -56 -44 -56 -51 dBm dBm dBm dBm Maximum output power. Complies with EN 300 328, EN 300 440, FCC CFR47 Part 15 and ARIB STD-T-66 Error Vector Magnitude (EVM) 11 % Measured as defined by [1] [1] requires max. 35 % Optimum load impedance 95 + j187 Ω Differential impedance as seen from the RF-port (RF_P and RF_N) towards the antenna. For matching details see the Input / Output Matching section on page 54.

6.3 Receive Section

Parameter Min. Typ. Max. Unit Condition / Note Receiver Sensitivity -90 -95 dBm PER = 1%, as specified by [1] Measured in a 50Ω single-ended load through a balun. [1] requires –85 dBm Saturation (maximum input level) 0 10 dBm PER = 1%, as specified by [1] Measured in a 50Ω single–ended load through a balun. [1] requires –20 dBm Adjacent channel rejection + 5 MHz channel spacing dB Wanted signal @ -82 dBm, adjacent modulated channel at +5 MHz, PER = 1 %, as specified by [1]. [1] requires 0 dB Adjacent channel rejection - 5 MHz channel spacing dB Wanted signal @ -82 dBm, adjacent modulated channel at -5 MHz, PER = 1 %, as specified by [1]. [1] requires 0 dB Alternate channel rejection + 10 MHz channel spacing dB Wanted signal @ -82 dBm, adjacent modulated channel at +10 MHz, PER = 1 %, as specified by [1] [1] requires 30 dB Alternate channel rejection - 10 MHz channel spacing dB Wanted signal @ -82 dBm, adjacent modulated channel at -10 MHz, PER = 1 %, as specified by [1] [1] requires 30 dB Channel rejection ≥ + 15 MHz ≤ - 15 MHz dB dB Wanted signal @ -82 dBm. Undesired signal is an IEEE 802.15.4 modulated channel, stepped through all channels from 2405 to 2480 MHz. Signal level for PER = 1%. Co-channel rejection dB Wanted signal @ -82 dBm. Undesired signal is an IEEE 802.15.4 modulated at the same frequency as the desired signal. Signal level for PER = 1%. Blocking / Desensitisation +/- 5 MHz from band edge +/- 20 MHz from band edge +/- 30 MHz from band edge +/- 50 MHz from band edge -28 -28 -27 -28 dBm dBm dBm dBm Wanted signal 3 dB above the sensitivity level, CW jammer, PER = 1%. Complies with EN 300 440 class 2. Spurious emission 30 – 1000 MHz 1 – 12.75 GHz -73 -58 dBm dBm Conducted measurement in a 50 Ω single ended load. Measured according to EN 300 328, EN 300 440 class 2, FCC CFR47, Part 15 and ARIB STD-T-66

Parameter Min. Typ. Max. Unit Condition / Note Frequency error tolerance -300 300 kHz Difference between centre frequency of the received RF signal and local oscillator frequency [1] requires 200 kHz Symbol rate error tolerance 120 ppm Difference between incoming symbol rate and the internally generated symbol rate [1] requires 80 ppm Data latency 3 µs Processing delay in receiver. Time from complete transmission of SFD until complete reception of SFD, i.e. from SFD goes active on transmitter until active on receiver.

6.4 RSSI / Carrier Sense

Parameter Min. Typ. Max. Unit Condition / Note Carrier sense level − 77 dBm Programmable in RSSI.CCA_THR RSSI dynamic range 100 dB The range is approximately from –100 dBm to 0 dBm RSSI accuracy ± 6 dB See page 48 for details RSSI linearity ± 3 dB RSSI average time 128 µs 8 symbol periods, as specified by [1]

6.5 IF Section

Parameter Min. Typ. Max. Unit Condition / Note Intermediate frequency (IF) 2 MHz

6.6 Frequency Synthesizer Section

Parameter Min. Typ. Max. Unit Condition / Note Crystal oscillator frequency 16 MHz See page 53 for details. Crystal frequency accuracy requirement - 40 40 ppm Including aging and temperature dependency, as specified by [1] Crystal operation Parallel C381 and C391 are loading capacitors, see page 53

Parameter Min. Typ. Max. Unit Condition / Note Crystal load capacitance 12 16 20 pF 16 pF recommended Crystal ESR 60 Ω Crystal oscillator start-up time 1.0 ms 16 pF load Phase noise −109 −117 −117 −117 dBc/Hz dBc/Hz dBc/Hz dBc/Hz Unmodulated carrier At ±1 MHz offset from carrier At ±2 MHz offset from carrier At ±3 MHz offset from carrier At ±5 MHz offset from carrier PLL loop bandwidth 100 kHz PLL lock time 192 µs The startup time from the crystal oscillator is running and RX / TX turnaround time

6.7 Digital Inputs/Outputs

Parameter Min. Typ. Max. Unit Condition / Note General Signal levels are referred to the voltage level at pin DVDD3.3 Logic "0" input voltage 0 0.3* DVDD V Logic "1" input voltage 0.7* DVDD DVDD V Logic "0" output voltage 0

0.4 V Output current −8 mA,

3.3 V supply voltage

Logic "1" output voltage 2.5 VDD V Output current 8 mA, Logic "0" input current NA −1 µA Input signal equals GND Logic "1" input current NA 1 µA Input signal equals VDD FIFO setup time 20 ns TX unbuffered mode, minimum time FIFO must be ready before the positive edge of FIFOP FIFO hold time 10 ns TX unbuffered mode, minimum time FIFO must be held after the positive edge of FIFOP Serial interface pins (SCLK, SI, SO and CSn) timing specification See Table 4 on page 28

6.8 Voltage Regulator

Parameter Min. Typ. Max. Unit Condition / Note General Note that the internal voltage regulator can only supply CC2420 and no external circuitry. Input Voltage 2.1 3.0 3.6 V On the VREG_IN pin Output Voltage 1.7 1.8 1.9 V On the VREG_OUT pin Quiescent current 13 20 29 µA No current drawn from the VREG_OUT pin. Min and max numbers include 2.1 through 3.6 V input voltage Start-up time 0.3 0.6 ms

6.9 Battery Monitor

Parameter Min. Typ. Max. Unit Condition / Note Current consumption 6 30 90 µA When enabled Start-up time 100 µs Voltage regulator already enabled Settling time 2 µs New toggle voltage programmed Step size 50 mV Hysteresis 10 mV Absolute accuracy -80 80 mV May be software calibrated for known reference voltage Relative accuracy -50 50 mV

6.10 Power Supply

Parameter Min. Typ. Max. Unit Condition / Note Current consumption in different modes (see Figure 25, page 44) Voltage regulator off (OFF) Power Down mode (PD) Idle mode (IDLE) 0.02 426 µA µA µA Current drawn from VREG_IN, through voltage regulator Voltage regulator off Voltage regulator on Including crystal oscillator and voltage regulator Current Consumption, receive mode 18.8 mA

Parameter Min. Typ. Max. Unit Condition / Note Current Consumption, transmit mode: P = -25 dBm P = -15 dBm P = -10 dBm P = −5 dBm P = 0 dBm 8.5 9.9 17.4 mA mA mA mA mA The output power is delivered differentially to a 50 Ω singled ended load through a balun, see also page 54.

7 Pin Assignment

Figure 1. CC2420 Pinout – Top View

1 VCO_GUARD Power (analog) Connection of guard ring for VCO (to AVDD) shielding

5 GND Ground (analog) Grounded pin for RF shielding

6 RF_P RF I/O Positive RF input/output signal to LNA/from PA in

8 RF_N RF I/O Negative RF input/output signal to LNA/from PA in

9 GND Ground (analog) Grounded pin for RF shielding

11 NC - Not Connected

12 NC - Not Connected

13 NC - Not Connected

Pin Pin Name Pin type Pin Description

16 NC - Not Connected

17 AVDD_ADC Power (analog) 1.8 V Power supply for analog parts of ADCs and DACs 18 DVDD_ADC Power (digital) 1.8 V Power supply fo r digital parts of receive ADCs

19 DGND_GUARD Ground (digital) Ground connection fo r digital noise isolation

20 DGUARD Power (digital) 1.8 V Power supply c onnection for digital noise isolation

21 RESETn Digital Input Asynchronous, active low digital reset

22 DGND Ground (digital) Ground connection for digital core and pads

23 DSUB_PADS Ground (digital) Substrate connection for digital pads

24 DSUB_CORE Ground (digital) Substrate c onnection for digital modules

25 DVDD3.3 Power (digital) 3.3 V Power supply for digital I/Os 26 DVDD1.8 Power (digital) 1.8 V Power supply for digital core

27 SFD Digital output SFD (Start of Frame Delimiter) / digital mux output

28 CCA Digital output CCA (Clear Channel Assessment) / digital mux output

29 FIFOP Digital output Active when number of bytes in FIFO exceeds threshold /

serial RF clock output in test mode

30 FIFO Digital I/O Active when data in FIFO /

serial RF data input / output in test mode

31 CSn Digital input SPI Chip select, active low

32 SCLK Digital input SPI Clock input, up to 10 MHz

33 SI Digital input SPI Slave Input. Sa mpled on the positive edge of SCLK

34 SO Digital output

(tristate) SPI Slave Output. Updated on the negative edge of SCLK. Tristate when CSn high. 35 DVDD_RAM Power (digital) 1.8 V Power supply for digital RAM

36 NC - Not Connected

37 AVDD_XOSC16 Power (analog) 1.8 V crystal oscillator power supply

38 XOSC16_Q2 Analog I/O 16 MHz Crystal oscillator pin 2

39 XOSC16_Q1 Analog I/O 16 MHz Crystal oscillator pin 1 or external clock input

40 NC - Not Connected

41 VREG_EN Digital input Voltage regulator enable, active high, held at VREG_IN

voltage level when active. Note that VREG_EN is relative VREG_IN, not DVDD3.3. 42 VREG_OUT Power output Voltage regulator 1.8 V power supply output 43 VREG_IN Power (analog) Voltage regulator 2.1 to 3.6 V power supply input 44 AVDD_IF1 Power (analog) 1.8 V Power supply for transmit / receive IF chain

45 R_BIAS Analog output External precision resistor, 43 kΩ, ± 1 %

46 ATEST2 Analog I/O Analog test I/O for prototype and production testing

47 ATEST1 Analog I/O Analog test I/O for prototype and production testing

48 AVDD_CHP Power (analog) 1.8 V Power suppl y for phase detector and charge pump NOTES: The exposed die attach pad must be connected to a solid ground plane as this is the main ground connection for the chip.

8 Circuit Description

16 MHz

Figure 2. CC2420 simplified block diagram synchronisation are performed digitally. received data in a 128 byte receive FIFO. SPI interface. CRC is verified in hardware. digital-to-analog converters (DACs). RF_N through an external DC path.

and Q LO signals to the down-conversion mixers in receive mode and up-conversion mixers in transmit mode. The VCO operates in the frequency range 4800 –

4966 MHz, and the frequency is divided by

two when split in I and Q. A crystal must be connected to XOSC16_Q1 and XOSC16_Q2 and provides the reference frequency for the synthesizer. A digital lock signal is available from the PLL. The digital baseband includes support for frame handling, address recognition, data buffering and MAC security. The 4-wire SPI serial interface is used for configuration and data buffering. An on-chip voltage regulator delivers the regulated 1.8 V supply voltage. The voltage regulator may be enabled / disabled through a separate pin. A battery monitor may optionally be used to monitor the unregulated power supply voltage. The battery monitor is configurable through the SPI interface.

9 Application Circuit

Few external components are required for the operation of CC2420. A typical application circuit is shown in Figure 4. The external components shown are described in Table 1 and typical values are given in Table 2. Note that most decoupling capacitors are not shown on the application circuits. For the complete reference design please refer to Texas Instrument’s web site: http://www.ti.com

9.1 Input / output matching

The RF input/output is high impedance and differential. The optimum differential load for the RF port is 95+j187 Ω. When using an unbalanced antenna such as a monopole, a balun should be used in order to optimise performance. The balun can be implemented using low-cost discrete inductors and capacitors only or in combination with transmission lines. Figure 3 shows the balun implemented in a two-layer reference design. It consists of a half wave transmission line, C81, L61, L71 and L81. The circuit will present the optimum RF termination to CC2420 with a 50 Ω load on the antenna connection. This circuit has improved EVM performance, sensitivity and harmonic suppression compared to the design in Figure 4. Please refer to the input/output matching section on page 54 for more details. The balun in Figure 4 consists of C61, C62, C71, C81, L61, L62 and L81, and will present the optimum RF termination to CC2420 with a 50 Ω load on the antenna connection. A low pass filter may be added to add margin to the FCC requirement on second harmonic level. If a balanced antenna such as a folded dipole is used, the balun can be omitted. If the antenna also provides a DC path from the TXRX_SWITCH pin to the RF pins, inductors are not needed for DC bias. Figure 5 shows a suggested application circuit using a differential antenna. The antenna type is a standard folded dipole. The dipole has a virtual ground point; hence bias is provided without degradation in antenna performance.

9.2 Bias resistor

The bias resistor R451 is used to set an accurate bias current.

9.3 Crystal

An external crystal with two loading capacitors (C381 and C391) is used for the crystal oscillator. See page 53 for details.

9.4 Voltage regulator

The on chip voltage regulator supplies all 1.8 V power supply inputs. C42 is required for stability of the regulator. A series resistor may be used to comply with the ESR requirement.

9.5 Power supply decoupling and

Proper power supply decoupling must be used for optimum performance. The placement and size of the decoupling capacitors and the power supply filtering are very important to achieve the best performance in an application. Texas Instruments provides a compact reference design that should be followed very closely..

Table 1. Overview of external components Figure 3. Typical application circuit with transmission line balun for single-ended

Figure 4. Typical application circuit with discrete balun for single-ended operation

Figure 5. Suggested application circuit with differential antenna (folded dipole)

16 MHz crystal, 16 pF load

16 MHz crystal, 16 pF load (CL),

Table 2. Bill of materials for the application circuits

description, please refer to [1]. are illustrated at block level in Figure 6 [1]. most significant byte it transmitted first. Figure 6. Modulation and spreading functions [1] Table 3. IEEE 802.15.4 symbol-to-chip mapping [1] illustrated for the zero-symbol in Figure 7.

Figure 7. I / Q Phases when transmitting a zero-symbol chip sequence, TC = 0.5 µs

11 Configuration Overview

• Receive / transmit mode
• RF channel selection
• RF output power
• Power-down / power-up mode
• Crystal oscillator power-up / power down
• Clear Channel Assessment mode
• Packet handling hardware support
• Encryption / Authentication modes

12 Evaluation Software

Figure 8. SmartRF Studio user interface

13 4-wire Serial Configuration and Data Interface CC2420 is configured via a simple 4-wire SPI-compatible interface (pins SI, SO, SCLK and CSn) where CC2420 is the slave. This interface is also used to read and write buffered data (see page 39). All address and data transfer on the SPI interface is done most significant bit first.

13.1 Pin configuration

The digital inputs SCLK, SI and CSn are high-impedance inputs (no internal pull- up) and should have external pull-ups if not driven. SO is high-impedance when CSn is high. An external pull-up should be used at SO to prevent floating input at microcontroller. Unused I/O pins on the MCU can be set to outputs with a fixed ‘0’ level to avoid leakage currents.

13.2 Register access

There are 33 16-bit configuration and status registers, 15 command strobe registers, and two 8-bit registers to access the separate transmit and receive FIFOs. Each of the 50 registers is addressed by a 6-bit address. The RAM/Register bit (bit 7) must be cleared for register access. The Read/Write bit (bit 6) selects a read or a write operation and makes up the 8-bit address field together with the 6-bit address. In each register read or write cycle, 24 bits are sent on the SI-line. The CSn pin (Chip Select, active low) must be kept low during this transfer. The bit to be sent first is the RAM/Register bit (set to 0 for register access), followed by the R/W bit (0 for write, 1 for read). The following 6 bits are the address-bits (A5:0 ). A5 is the most significant bit of the address and is sent first. The 16 data-bits are then transferred (D15:0), also MSB first. See Figure 9 for an illustration. The configuration registers can also be read by the microcontroller via the same configuration interface. The R/W bit must be set high to initiate the data read-back. CC2420 then returns the data from the addressed register on the 16 clock cycles following the register address. The SO pin is used as the data output and must be configured as an input by the microcontroller. The timing for the programming is also shown in Figure 9 with reference to Table 4. The clocking of the data on SI into the CC2420 is done on the positive edge of SCLK. When the last bit, D0, of the 16 data-bits has been written, the data word is loaded in the internal configuration register. Multiple registers may be written without releasing CSn, as described in the Multiple SPI access section on page 31. The register data will be retained during power down mode, but not when the power-supply is turned off (e.g. by disabling the voltage regulator using the VREG_EN pin). The registers can be programmed in any order.

1 A6 A5 A4 A3 A2 A0A1 B1 B0 0 X X X X X DW7 DW6 DW5 DW4 DW3 DW2 DW1 DW0

1 A6 A5 A4 A3 A2 A0A1

Figure 9. SPI timing diagram

10 MHz

tcl 25 ns The minimum time SCLK must be low. tch 25 ns The minimum time SCLK must be high. before the positive edge of SCLK. Note: The set-up- and hold-times refer to 50% of VDD. Table 4. SPI timing specification

13.3 Status byte

which are described in Table 5.

6 XOSC16M_STABLE Indicates whether the 16 MHz oscillator is running or not

5 TX_UNDERFLOW Indicates whether an FIFO underflow has occurred during

4 ENC_BUSY Indicates whether the encryption module is busy

3 TX_ACTIVE Indicates whether RF transmission is active

2 LOCK Indicates whether the frequency synthesizer PLL is in lock or not

1 RSSI_VALID Indicates whether the RSSI value is valid or not. Table 5. Status byte returned during address transfer and TXFIFO writing

13.4 Command strobes

strobes are listed in Table 11 on page 62.

13.5 RAM access

each, while the security bank is 112 bytes. RAM/Register bit as shown in Figure 9. Table 6. The lower 256 bytes are used to Multiple register read or write DATA8MSBADDR DATA8LSB DATA8MSB DATA8LSB... Read or write n bytes from/to RF FIFO: DATAbyte0ADDRFIFO DATAbyte1 DATAbyte2 DATAbyte3 DATAbyte n-2 DATAbyte n-1... Read or write n bytes from/to RAM: ADDRHRAMADDRLRAM DATAADDR DATAADDR+1 DATAADDR+2 DATAADDR+n... FIFO and RAM access must be terminated with setting the CSn pin high. Figure 10. Configuration registers write and read operations via SPI

SHORTADR 16-bit Short address, used for address recognition. PANID 16-bit PAN identifier, used for address recognition. transmitter counter for in-line encryption. receiver counter for in-line decryption. Table 6. CC2420 RAM Memory Space

13.6 FIFO access

(decryption / authentication). data byte on SO, as shown in Figure 9. one operation, as with the RAM access. underflow flag in the status byte.

13.7 Multiple SPI access

continuously without setting CSn high. terminated by setting CSn high.

Figure 11. Multiple SPI Access Example

14 Microcontroller Interface and Pin Description

• Program CC2420 into different modes, read and write buffered data, and read back status information via the 4-wire SPI-bus configuration interface (SI, SO, SCLK and CSn).
• Interface to the receive and transmit FIFOs using the FIFO and FIFOP status pins.
• Interface to the CCA pin for clear channel assessment.
• Interface to the SFD pin for timing information (particularly for beaconing networks).

14.1 Configuration interface

must be microcontroller outputs. prevent the inputs from floating. Figure 12. Microcontroller interface example

14.2 Receive mode

In receive mode, the SFD pin goes active after the start of frame delimiter (SFD) field has been completely received. If address recognition is disabled or is successful, the SFD pin goes inactive again only after the last byte of the MPDU has been received. If the received frame fails address recognition, the SFD pin goes inactive immediately. This is illustrated in Figure 13. The FIFO pin is active when there are one or more data bytes in the RXFIFO. The first byte to be stored in the RXFIFO is the length field of the rece ived frame, i.e. the FIFO pin goes active when the length field is written to the RXFIFO. The FIFO pin then remains active until the RXFIFO is empty. If a previously received frame is completely or partially inside the RXFIFO, the FIFO pin will remain active until the RXFIFO is empty. The FIFOP pin is active when the number of unread bytes in the RXFIFO exceeds the threshold programmed into IOCFG0.FIFOP_THR. When address recognition is enabled the FIFOP pin will remain inactive until the incoming frame passes address recognition, even if the number of bytes in the RXFIFO exceeds the programmed threshold. The FIFOP pin will also go active when the last byte of a new packet is received, even if the threshold is not exceeded. If so, the FIFOP pin will go inactive once one byte has been read out of the RXFIFO. When address recognition is enabled, data should not be read out of the RXFIFO before the address is completely received, since the frame may be automatically flushed by CC2420 if it fails address recognition. This may be handled by using the FIFOP pin, since this pin does not go active until the frame passes address recognition. Figure 14 shows an example of pin activity when reading a packet from the RXFIFO. In this example, the packet size is 8 bytes, IOCFG0.FIFOP_THR = 3 and MODEMCTRL0.AUTOCRC is set. The length will be 8 bytes, RSSI will contain the average RSSI level during reception of the packet and FCS/corr contains information of FCS check result and the correlation levels.

14.3 RXFIFO overflow

The RXFIFO can only contain a maximum of 128 bytes at a given time. This may be divided between multiple frames, as long as the total number of bytes is 128 or less. If an overflow occurs in the RXFIFO, this is signalled to the microcontroller by making the FIFO pin go inactive while the FIFOP pin is active. Data already in the RXFIFO will not be affected by the overflow, i.e. frames already received may be read out. A SFLUSHRX command strobe is required after an RXFIFO overflow to enable reception of new data. Note that the SFLUSHRX command strobe should be issued twice to ensure that the SFD pin goes back to its inactive state. For security enabled frames, the MAC layer must read the source address of the received frame before it can decide which key to use to decrypt or authenticate. This data must therefore not be overwritten even if it has been read out of the RXFIFO by the microcontroller. If the SECCTRL0.RXFIFO_PROTECTION control bit is set, CC2420 also protects the frame header of security enabled frames until decryption has been performed. If no MAC security is used or if it is implemented outside the CC2420, this bit may be cleared to achieve optimal use of the RXFIFO.

Figure 13. Pin activity examples during receive Figure 14. Example of pin activity when reading RXFIFO.

14.4 Transmit mode

both the transmitter and the receiver.

Figure 15. Pin activity example during transmit

14.5 General control and status pins

microcontroller interrupt pin. been completely detected / transmitted.

15 Demodulator, Symbol Sync hroniser and Data Decision

demodulator is shown in Figure 16. included for enhanced performance. Soft decision is used at the chip level, i.e. 250 kbps generated by the receiver. without performance degradation.

Figure 16. Demodulator Simplified Block Diagram

16 Frame Format

CC2420 is set up to comply with this. command frames) are included in [1]. Figure 17. Schematic view of the IEEE 802.15.4 Frame Format [1]

16.1 Synchronisation header

transmitted first in all transmit modes. the IEEE 802.15.4 specification.

make CC2420 compliant with [1]. stored in the receive buffer (RXFIFO). Each box corresponds to 4 bits. Hence the preamble corresponds to 8 x 4 ''0' s or 4 bytes with the value 0. Figure 18. Transmitted Synchronisation Header

16.2 Length field

defines the number of bytes in the MPDU. includes the MIC if authentication is used. [1], and should be set to zero. FIFO access section on page 31.

16.3 MAC protocol data unit

1. Please refer to [1] for details.

inserted and verified by software. Recognition section on page 41. Figure 19. Format of the Frame Control Field (FCF) [1]

16.4 Frame check sequence

is illustrated in Figure 21. over the first 8 symbols following the SFD. Figure 20. CC2420 Frame Check Sequence (FCS) hardware implementation [1]

Figure 21. Data in RXFIFO when MDMCTRL0.AUTOCRC is set

17 RF Data Buffering

MDMCTRL1.RX_MODE control bits. modes are available for test purposes.

17.1 Buffered transmit mode

written to the transmit buffer for all frames. STXON or STXONCCA command strobe. symbol periods after the command strobe. bytes are written to the TXFIFO. SFLUSHTX command strobe is required.

17.2 Buffered receive mode

17.3 Unbuffered, serial mode

evaluation / debugging purposes only. active. This is illustrated in Figure 22. frame delimiter has been detected. Figure 22. Unbuffered test mode, pin activity

18 Address Recognition

CC2420 includes hardware support for address recognition, as specified in [1]. Hardware address recognition may be enabled / disabled using the MDMCTRL0.ADR_DECODE control bit. Address recognition is based on the following requirements, listed from section 7.5.6.2 in [1]:

• The frame type subfield shall not contain an illegal frame type
• If the frame type indicates that the frame is a beacon frame, the source PAN identifier shall match macPANId unless macPANId is equal to 0xFFFF, in which case the beacon frame shall be accepted regardless of the source PAN identifier.
• If a destination PAN identifier is included in the frame, it shall match macPANId or shall be the broadcast PAN identifier (0xFFFF).
• If a short destination address is included in the frame, it shall match either macShortAddress or the broadcast address (0xFFFF). Otherwise if an extended destination address is included in the frame, it shall match aExtendedAddress.
• If only source addressing fields are included in a data or MAC command frame, the frame shall only be accepted if the device is a PAN coordinator and the source PAN identifier matches macPANId. If any of the above requirements are not satisfied and address recognition is enabled, CC2420 will disregard the incoming frame and flush the data from the RXFIFO. Only data from the rejected frame is flushed, data from previously accepted frames may still be in the RXFIFO. The IOCFG0.BCN_ACCEPT control bit must be set when the PAN identifier programmed into CC2420 RAM is equal to 0xFFFF and cleared otherwise. This particularly applies to active and passive scans as defined by [1], which requires all received beacons to be processed by the MAC sublayer. Incoming frames with reserved frame types (FCF frame type subfield is 4, 5, 6 or 7) is however accepted if the RESERVED_FRAME_MODE control bit in MDMCTRL0 is set. In this case, no further address recognition is performed on these frames. This option is included for future expansions of the IEEE 802.15.4 standard. If a frame is rejected, CC2420 will only start searching for a new frame after the rejected frame has been completely received (as defined by the length field) to avoid detecting false SFDs within the frame. The MDMCTRL0.PAN_COORDINATOR control bit must be correctly set, since parts of the address recognition procedure requires knowledge about whether the current device is a PAN coordinator or not.

19 Acknowledge Frames

CC2420 includes hardware support for transmitting acknowledge frames, as specified in [1]. Figure 23 shows the format of the acknowledge frame. If MDMCTRL0.AUTOACK is enabled, an acknowledge frame is transmitted for all incoming frames accepted by the address recognition with the acknowledge request flag set and a valid CRC. AUTOACK therefore does not make sense unless also ADR_DECODE and AUTOCRC are enabled. The sequence number is copied from the incoming frame.

20 Radio control state machine

CC2420 has a built-in state machine that is used to switch between different operational states (modes). The change of state is done either by using command strobes or by internal events such as SFD detected in receive mode. The radio control state machine states are shown in Figure 25. The numbers in brackets refer to the state number readable in the FSMSTATE status register. Reading the FSMSTATE status register is primarily for test / debug purposes. Before using the radio in either RX or TX mode, the voltage regulator and crystal oscillator must be turned on and become stable. The voltage regulator and crystal oscillator start-up times are given in the Electrical Specifications section on page The crystal oscillator is controlled by accessing the SXOSCON / SXOSCOFF command strobes. The XOSC16M_STABLE bit in the status register returned during address transfer indicates whether the oscillator is running and stable or not (see Table 5). This status register can be polled when waiting for the oscillator to start. For test purposes, the frequency synthesizer (FS) can also be manually calibrated and started by using the STXCAL command strobe register. This will not start a transmission before a STXON command strobe is issued. This is not shown in Figure 25. Enabling transmission is done by issuing a STXON or STXONCCA command strobe. Turning off RF can be accomplished by using one of the SRFOFF or SXOSCOFF command strobe registers. After reset the CC2420 is in Power Down mode. All configurati on registers can then be programmed in order to make the chip ready to operate at the correct frequency and mode. Due to the very fast start-up time, CC2420 can remain in Power Down until a transmission session is requested. As also described in the 4-wire Serial Configuration and Data Interface section on page 27, the crystal oscillator must be running (IDLE) in order to have access to the RAM and FIFOs.

Figure 25. Radio control states

21 MAC Security Operations (E ncryption and Authentication)

is encrypted to a 128 bit ciphertext. operation will be completed.

802.15.4 MAC security operations, please

21.1 Keys

SEC_SAKEYSEL control bits (SECCTRL0). decided for each particular application. loading keys may also be selected.

21.2 Nonce / counter

respectively. They are both 16 bytes. controlled by a layer above the MAC layer. source address is the 64 bit IEEE address. Table 7. IEEE 802.15.4 Nonce [1] 0x0001 for compliance with [1].

generated as shown in Figure 26. Figure 26. CC2420 Security Flag Byte

21.3 Stand-alone encryption

seen from Table 6 on page 31. thereby overwriting the plaintext.

21.4 In-line security operations

• Disabled
• CBC-MAC (authentication)
• CTR (encryption / decryption)
• CCM (authentication and encryption / decryption) When enabled, TX in-line security is started in one of two ways:
• Issue a STXENC command strobe. In- line security will be performed within the TXFIFO, but a RF transmission will not be started. Ciphertext may be read back using RAM read operations.
• Issue a STXON or STXONCCA command strobe. In-line security will be performed within the TXFIFO and a RF transmission of the ciphertext is started. When enabled, RX in-line security is started as follows:
• Issue a SRXDEC command strobe. The first frame in the RXFIFO is then decrypted / authenticated as set by the current security mode.

RX in-line security operations are always performed on the first frame currently inside the RXFIFO, even if parts of this have already been read out over the SPI interface. This allows the receiver to first read the source address out to decide which key to use before doing authentication of the complete frame. In CTR or CCM mode it is of course important that byte s to be decrypted are not read out before the security operation is started. When the SRXDEC command strobe is issued, the FIFO and FIFOP pins will go inactive. This is to indicate to the microcontroller that no further data may be read out before the next byte to be read has undergone the requested security operation. The frame in the RXFIFO may be received over RF or it may be written into the RXFIFO over the SPI interface for debugging or higher layer security operations.

21.5 CTR mode encryption /

CTR mode encryption / decryption is performed by CC2420 on MAC frames within the TXFIFO / RXFIFO respectively. SECCTRL1.SEC_TXL / SEC_RXL sets the number of bytes between the length field and the first byte to be encrypted / decrypted respectively. This controls the number of plaintext bytes in the current frame. For IEEE 802.15.4 MAC encryption, only the MAC payload (see Figure 17 on page 36) should be encrypted, so SEC_TXL / SEC_RXL is set to 3 + (0 to 20) depending on the address information in the current frame. When encryption is init iated, the plaintext in the TXFIFO is then encrypted as specified by [1]. The encryption module will encrypt all the plaintext currently available, and wait if not everything is pre- buffered. The encryption operation may also be started wit hout any data in the TXFIFO at all, and data will be encrypted as it is written to the TXFIFO. When decryption is initiated with a SRXDEC command strobe, the ciphertext of the RXFIFO is then decrypted as specified by [1].

21.6 CBC-MAC

CBC-MAC in-line authentication is provided by CC2420 hardware. SECCTRL0.SEC_M sets the MIC length M, encoded as (M-2)/2. When enabling CBC-MAC in-line TXFIFO authentication, the generated MIC is written to the TXFIFO for transmission. The frame length must include the MIC. SECCTRL1.SEC_TXL / SEC_RXL sets the number of bytes between the length field and the first byte to be authenticated, normally set to 0 for MAC authentication. SECCTRL0.SEC_CBC_HEAD defines if the authentication length is used as the first byte of data to be authenticated or not. This bit should be set for compliance with [1]. When enabling CBC-MAC in-line RXFIFO authentication, the generated MIC is compared to the MIC in the RXFIFO. The last byte of the MIC is replaced in the RXFIFO with:

• 0x00 if the MIC is correct
• 0xFF if the MIC is incorrect The other bytes in the MIC are left unchanged in the RXFIFO.

21.7 CCM

CCM combines CTR mode encryption and CBC-MAC authentication in one operation. CCM is described in [3]. SECCTRL1.SEC_TXL / SEC_RXL sets the number of bytes after the length field to be authenticated but not encrypted. The MIC is generated and verified very much like with CBC-MAC described above. The only differences are from the requirements in [1] for CCM.

21.8 Timing Table 8 shows some examples of the time

Table 8. Security timing examples

22 Linear IF and AGC Settings

an analog VGA (variable gain amplifier). The gain of the VGA is digitally controlled.

23 RSSI / Energy Detection

enabled for at least 8 symbol periods. input power is approximately –65 dBm.

1. It can be seen from the figure that the

and has a dynamic range of about 100 dB. each symbol after RSSI has become valid.

Figure 27. Typical RSSI value vs. input power

24 Link Quality Indication

through 255, with at least 8 unique values.

25 Clear Channel Assessment

The clear channel assessment signal is based on the measured RSSI value and a programmable threshold. The clear channel assessment function is used to implement the CSMA-CA functionality specified in [1]. CCA is valid when the receiver has been enabled for at least 8 symbol periods. Carrier sense threshold level is programmed by RSSI.CCA_THR. The threshold value can be programmed in steps of 1 dB. A CCA hysteresis can also be programmed in the MDMCTRL0.CCA_HYST control bits. All 3 CCA modes specified by [1] are implemented in CC2420. They are set in MDMCTRL0.CCA_MODE, as can be seen in the register description. The different modes are:

0 Reserved

1 Clear channel when received energy is below

threshold.

2 Clear channel when not receiving valid IEEE

802.15.4 data.

3 Clear channel when energy is below threshold

and not receiving valid IEEE 802.15.4 data Clear channel assessment is available on the CCA output pin. CCA is active high, but the polarity may be changed by setting the IOCFG0.CCA_POLARITY control bit. Implementing CSMA-CA may easiest be done by using the STXONCCA command strobe, as described in the Radio control state machine section on page 43. Transmission will then only start if the channel is clear. The TX_ACTIVE status bit (see Table 5) may be used to detect the result of the CCA.

26 Frequency and Channel Programming

The operating frequency is set by programming the 10 bit frequency word located in FSCTRL.FREQ[9:0]. The operating frequency F C in MHz is given by: FC = 2048 + FSCTRL.FREQ[9:0] MHz The frequency can be programmed with 1 MHz resolution. In receive mode the actual LO frequency is F C – 2 MHz, since a 2 MHz IF is used. Direct conversion is used for transmission, so here the LO frequency equals F C. The 2 MHz IF is automatically set by CC2420, so the frequency programming is equal for RX and TX. IEEE 802.15.4 specifies 16 channels within the 2.4 GHz band, in 5 MHz steps, numbered 11 through 26. The RF frequency of channel k is given by [1]: F For operation in channel k, the FSCTRL.FREQ register should therefore be set to: FSCTRL.FREQ = 357 + 5 (k-11)

27 VCO and PLL Self-Calibration

27.1 VCO

27.2 PLL self-calibration

and the desired operating frequency.

28 Output Power Programming

Table 9. Output power settings and typical current consumption @ 2.45 GHz

29 Voltage Regulator

capability and noise considerations. voltage regulator enable pin VREG_EN. regulator is shown in Figure 28. Application Circuit section on page 19. the voltage regulator is disabled.

Figure 28. Voltage regulator, simplified schematic

30 Battery Monitor

Figure 29. Battery monitor, simplified schematic

when using the battery monitor. in the BATTMON.BATTMON_OK status bit. unsigned, positive number from 0 to 31.

31 Crystal Oscillator

when an external clock signal is used. L, specified for the crystal. capacitance is typically 2 pF - 5 pF. Figure 30. Typical component values for

Figure 30. Crystal oscillator circuit Table 10. Crystal oscillator component values

32 Input / Output Matching

shown in Figure 4 and Figure 5. Component values are given in Table 2. 180 degrees phase difference.

33 Transmitter Test Modes

test modes for performance evaluation. that the crystal oscillator has stabilised.

33.1 Unmodulated carrier

CC2420 is shown in Figure 31 below.

Figure 31. Single carrier output

33.2 Modulated spectrum

spectrum is then available on the RF pins. transmitted data sequence is 65535 bits. synchronisation, for correct reception.

Figure 32. Modulated spectrum plot

34 System Considerations and Guidelines

International regulations and national laws regulate the use of radio receivers and transmitters. SRDs (Short Range Devices) for license free operation are allowed to operate in the 2.4 GHz band worldwide. The most important regulations are ETSI EN 300 328 and EN 300 440 (Europe), FCC CFR-47 part 15.247 and 15.249 (USA), and ARIB STD-T66 (Japan).

34.1 Frequency hopping and multi-

The 2.4 GHz band is shared by many systems both in industrial, office and home environments. CC2420 uses direct sequence spread spectrum (DSSS) as defined by [1] to spread the output power, thereby making the communication link more robust even in a noisy environment. With CC2420 it is also possible to combine both DSSS and FHSS (frequency hopping spread spectrum) in a proprietary non- IEEE 802.15.4 system. This is achieved by reprogramming the operating frequency (see the Frequency and Channel Programming section on page 50) before enabling RX or TX. A frequency synchronisation scheme must then be implemented within the proprietary MAC layer to make the transmitter and receiver operate on the same RF channel.

34.2 Data burst transmissions

The data buffering in CC2420 lets the user have a lower data rate link between the microcontroller and the RF device than the RF bit rate of 250 kbps. This allows the microcontroller to buffer data at its own speed, reducing the workload and timing requirements. The relatively high data rate of CC2420 also reduces the average power consumption compared to the 868 / 915 MHz bands defined by [1], where only 20 / 40 kbps are available. CC2420 may be powered up a smaller portion of the time, so that the average power consumption is reduced for a given amount of data to be transferred.

34.3 Crystal accuracy and drift

A crystal accuracy of ±40 ppm is required for compliance with IEEE 802.15.4 [1]. This accuracy must also take ageing and temperature drift into consideration. A crystal with low temperature drift and low aging could be used without further compensation. A trimmer capacitor in the crystal oscillator circuit (in parallel with C7) could be used to set the initial frequency accurately. For non-IEEE 802.15.4 systems, the robust demodulator in CC2420 allows up to 120 ppm total frequency offset between the transmitter and receiver. This could e.g. relax the accuracy requirement to 60 ppm for each of the devices. Optionally in a star network topology, the FFD could be equipped with a more accurate crystal thereby relaxing the requirement on the RFD. This can make sense in systems where the RFDs ship in higher volumes than the FFDs.

34.4 Communication robustness

CC2420 provides very good adjacent, alternate and co channel rejection, image frequency suppression and blocking properties. The CC2420 performance is significantly better than the requirements imposed by [1]. These are highly important parameters for reliable operation in the 2.4 GHz band, since an increasing number of devices/systems are using this license free frequency band.

34.5 Communication security

The hardware encryption and authentication operations in CC2420 enable secure communication, which is required for many applications. Security operations require a lot of data processing, which is costly in an 8-bit microcontroller system. The hardware support within CC2420 enables a high level of security even with a low-cost 8 bit controller.

34.6 Low-cost systems

As the CC2420 provides 250 kbps multi- channel performance without any external filters, a very low- cost system can be made. A differential antenna will eliminate the need for a balun, and the DC biasing can be achieved in the antenna topology.

34.7 Battery operated systems

In low power applications, the CC2420 should be powered down when not being active. Extremely low power consumption may be achieved when disabling also the voltage regulator. This will require reprogramming of the register and RAM configuration.

34.8 BER / PER measurements

CC2420 includes test modes where data is received infinitely and output to pins (RX_MODE 2, see page 40). This mode may be used for Bit Error Rate (BER) measurements. However, the following actions must be taken to do such a measurement:

• A preamble and SFD sequence must be used, even if pseudo random data is transmitted, since receiving the DSSS modulated signal requires symbol synchronisation, not bit synchronisation like e.g. in 2FSK systems. The SYNCWORD may be set to another value to fit to the measurement setup if necessary.
• The data transmitted over air must be spread according to [1] and the description on page 24. This means that the transmitter used during measurements must be able to do spreading of the bit data to chip data. Remember that the chip sequence transmitted by the test setup is not the same as the bit sequence, which is output by CC2420.
• When operating at or below the sensitivity limit, CC2420 may loose symbol synchronisation in infinite receive mode. A new SFD and restart of the receiver may be required to re-gain synchronisation. In an IEEE 802.15.4 system, all communication is based on packets. The sensitivity limit specified by [1] is based on Packet Error Rate (PER) measurements instead of BER. This is a more accurate measurement of the true RF performance since it mirrors the wa y the actual system operates. It is recommended to perform PER measurements instead of BER measurements to evaluate the performance of IEEE 802.15.4 systems. To do PER measurements, the following may be used as a guideline:
• A valid preamble, SFD and length field must be used for each packet.
• The PSDU (see Figure 17 on page 36) length should be 20 bytes for sensitivity measurements as specified by [1].
• The sensitivity limit specified by [1] is the RF level resulting in a 1% PER. The packet sample space for a given measurement must then be >> 100 to have a sufficiently large sample space. E.g. at least 1000 packets should be used to measure the sensitivity.
• The data transmitted over air must be spread according to [1] and the description on page 24. Pre- generated packets may be used, although [1] requires that the PER is averaged over random PSDU data.
• The CC2420 receive FIFO may be used to buffer data received during PER measurements, since it is able to buffer up to 128 bytes.
• The MDMCTRL1.CORR_THR control register is by default set to 20, as described in the Demodulator, Symbol Synchroniser and Data Decision section.

• The RXCTRL1.RXBPF_LOCUR control bit should be set to 1. The simplest way of making a PER measurement will be to use another CC2420 as the reference transmitter. However, this makes it difficult to measure the exact receiver performance. Using a signal generator, this may either be set up as O-QPSK with half-sine shaping or as MSK. If using O-QPSK, the phases must be selected according to [1]. If using MSK, the chip sequence must be modified such that the modulated MSK signal has the same phase shifts as the O- QPSK sequence previously defined. For a desired symbol sequence s 0, s1, … , sn-1 of length n symbols, the desired chip sequence c0, c1, c2, …, c 32n-1 of length 32n is found using table lookup from Table 3 on page 24. It can be seen from comparing the phase shifts of the O-QPSK signal with the frequency of a MSK signal that the MSK chip sequence is generated as: 0 xnor c 1), (c 1 xor c 2), (c 2 xnor c 3), … , (c32n-1 xor c 32n) where c 32n may be arbitrarily selected.

35 PCB Layout Recommendations

Following Texas Instruments’s reference design is highly recommended. In our reference design, the top layer is used for signal routing, and the open areas are filled with metallisation connected to ground using several vias. Layer 2 has not been used in our CC2420 reference designs. Layer 3 is used for power routing and the bottom layer serves as ground plane with a little routing. The area under the chip is used for grounding and must be well connected to the ground plane with several vias. The ground pins should be connected to ground as close as possible to the package pin using individual vias. The de- coupling capacitors should also be placed as close as possible to the supply pins and connected to the ground plane by separate vias. Supply power filtering is very important. The external components should be as small as possible (0402 is recommended) and surface mount devices must be used. Caution should be used when placing the microcontroller in order to avoid interference with the RF circuitry. A Development Kit with a fully assembled Evaluation Module is available. It is strongly advised that this reference layout is followed very closely in order to get the best performance. The schematic, BOM and layout Gerber files for the reference designs are all available from the Texas Instruments website.

36 Antenna Considerations

CC2420 can be used together with various types of antennas. A differential antenna like a dipole would be the easiest to interface not needing a balun (balanced to un-balanced transformation network). The length of the λ/2-dipole antenna is given by: L = 14250 / f where f is in MHz, giving the length in cm. An antenna for 2450 MHz should be 5.8 cm. Each arm is therefore 2.9 cm. Other commonly used antennas for short- range communication are monopole, helical and loop antennas. The single- ended monopole and helical would require a balun network between the differential output and the antenna. Monopole antennas are resonant antennas with a length corresponding to one quarter of the electrical wavelength

(λ/4). They are very easy to design and can be implemented simply as a “piece of wire” or even integrated into the PCB. The length of the λ/4-monopole antenna is given by: L = 7125 / f where f is in MHz, giving the length in cm. An antenna for 2450 MHz should be 2.9 cm. Non-resonant monopole antennas shorter than λ/4 can also be used, but at the expense of range. In size and cost critical applications such an antenna may very well be integrated into the PCB. Enclosing the antenna in high dielectric constant material reduces the overall size of the antenna. Many vendors offer such antennas intended for PCB mounting. Helical antennas can be thought of as a combination of a monopole and a loop antenna. They are a good compromise in size critical applications. Helical antennas tend to be more difficult to optimize than the simple monopole. Loop antennas are easy to integrate into the PCB, but are less effective due to difficult impedance matching because of their very low radiation resistance. For low power applications the differential antenna is recommended giving the best range and because of its simplicity. The antenna should be connected as close as possible to the IC. If the antenna is located away from the RF pins the antenna should be matched to the feeding transmission line (50 Ω).

37 Configuration Registers

The configuration of CC2420 is done by programming the 16-bit configuration registers. Complete descriptions of the registers are given in the following tables. After chip reset (from the RESETn pin or programmable through the MAIN.RESETn configuration bit), all the registers have default values as shown in the tables. Note that the MAIN register is only reset by using the pin reset RESETn. When writing to this register, all bits will get the value written, not the default value. This also means that the MAIN.RESETn bit must be written both low and then high to perform a chip reset through the serial interface. 15 registers are Strobe Command Registers, listed first in Table 11 below. Accessing these registers will initiate the change of an internal state or mode. There are 33 normal 16-bits registers, also listed in Table 11. Many of these registers are for test purposes only, and need not be accessed for normal operation of CC2420. The FIFOs are accessed through two 8-bit registers, TXFIFO and RXFIFO. The TXFIFO register is write only. Data may still be read out of the TXFIFO through regular RAM access (see section RAM access section on page 29), but data is then not removed from the FIFO. Note that the crystal oscillator must be active for all FIFO and RAM access. During address transfer, and while data is being written to the TXFIFO, a status byte is returned on the serial data output pin SO. This status byte is described in Table 5 on page 29. All configuration and st atus registers are described in the tables following Table 11. Address Register Register type Description 0x00 SNOP S No Operation (has no other effect than reading out status-bits) 0x01 SXOSCON S Turn on the crystal oscillator (set XOSC16M_PD = 0 and BIAS_PD = 0) 0x02 STXCAL S Enable and calibrate frequency synthesizer for TX; Go from RX / TX to a wait state where only the synthesizer is running. 0x03 SRXON S Enable RX 0x04 STXON S Enable TX after calibration (if not already performed) Start TX in-line encryption if SPI_SEC_MODE ≠ 0 0x05 STXONCCA S If CCA indicates a clear channel: Enable calibration, then TX. Start in-line encryption if SPI_SEC_MODE ≠ 0 else do nothing 0x06 SRFOFF S Disable RX/TX and frequency synthesizer 0x07 SXOSCOFF S Turn off the crystal oscillator and RF 0x08 SFLUSHRX S Flush the RX FIFO buffer and reset the demodulator. Always read at least one byte from the RXFIFO before issuing the SFLUSHRX command strobe 0x09 SFLUSHTX S Flush the TX FIFO buffer 0x0A SACK S Send acknowledge frame, wi th pending field cleared. 0x0B SACKPEND S Send acknowledge frame, with pending field set. 0x0C SRXDEC S Start RXFIFO in-line decryption / authentication (as set by SPI_SEC_MODE) 0x0D STXENC S Start TXFIFO in-line encryption / authentication (as set by SPI_SEC_MODE), without starting TX.

Table 11. Configuration registers overview

MAIN (0x10) - Main Control Register Bit Field Name Reset R/W Description

15 RESETn 1 R/W Active low reset of the entire circuit should be applied before

doing anything else. Equivalent to using the RESETn reset pin. 14 ENC_RESETn 1 R/W Active low reset of the encryption module. (Test purposes only) 13 DEMOD_RESETn 1 R/W Active low reset of the demodulator module. (Test purposes only) 12 MOD_RESETn 1 R/W Active low reset of the modulator module. (Test purposes only) 11 FS_RESETn 1 R/W Active low reset of the frequency synthesizer module. (Test purposes only) 10:1 - 0 W0 Reserved, write as 0

0 XOSC16M_BYPASS 0 R/W Bypasses the crystal oscillator and uses a buffered version of the

signal on Q1 directly. This can be used to apply an external rail- rail clock signal to the Q1 pin.

MDMCTRL0 (0x11) - Modem Control Register 0 Bit Field Name Reset R/W Description 15:14 - 0 W0 Reserved, write as 0 13 RESERVED_FRAME_MODE 0 R/W Mode for accepting reserved IEE 802.15.4 frame types when address recognition is enabled (MDMCTRL0.ADR_DECODE = 1). 0 : Reserved frame types (100, 101, 110, 111) are rejected by address recognition. 1 : Reserved frame types (100, 101, 110, 111) are always accepted by address recognition. No further address decoding is done. When address recognition is disabled (MDMCTRL0.ADR_DECODE = 0), all frames are received and RESERVED_FRAME_MODE is don’t care. 12 PAN_COORDINATOR 0 R/W Should be set high when the device is a PAN Coordinator. Used for filtering packets with no destination address, as specified in 11 ADR_DECODE 1 R/W Hardware Address decode enable. 0 : Address decoding is disabled 1 : Address decoding is enabled 10:8 CCA_HYST[2:0] 2 R/W CCA Hysteresis in dB, values 0 through 7 dB 7:6 CCA_MODE[1:0] 3 R/W 0 : Reserved 1 : CCA=1 when RSSI_VAL < CCA_THR - CCA_HYST CCA=0 when RSSI_VAL ≥ CCA_THR 2 : CCA=1 when not receiving valid IEEE 802.15.4 data, CCA=0 otherwise 3 : CCA=1 when RSSI_VAL < CCA_THR - CCA_HYST and not receiving valid IEEE 802.15.4 data. CCA=0 when RSSI_VAL ≥ CCA_THR or receiving a packet

5 AUTOCRC 1 R/W In packet mode a CRC-16 (ITU-T) is calculated and is

transmitted after the last data byte in TX. In RX CRC is calculated and checked for validity.

4 AUTOACK 0 R/W If AUTOACK is set, all packets accepted by address recognition

with the acknowledge request flag set and a valid CRC are acknowledged 12 symbol periods after being received. 3:0 PREAMBLE_LENGTH [3:0]

2 R/W The number of preamble bytes (2 zero-symbols) to be sent in TX

mode prior to the SYNCWORD, encoded in steps of 2. The reset value of 2 is compliant with IEEE 802.15.4, since the 4 th zero byte is included in the SYNCWORD. 0 : 1 leading zero bytes (not recommended) 1 : 2 leading zero bytes (not recommended) 2 : 3 leading zero bytes (IEEE 802.15.4 compliant) 3 : 4 leading zero bytes 15 : 16 leading zero bytes

MDMCTRL1 (0x12)– Modem Control Register 1 Bit Field Name Reset R/W Description 15:11 - 0 W0 Reserved, write as 0. 10:6 CORR_THR[4:0] 20 R/W Demodulator correlator threshold value, required before SFD search. Note that on early CC2420 versions the reset value was 5 DEMOD_AVG_MODE 0 R/W Frequency offset average filter behaviour. 0 : Lock frequency offset filter after preamble match 1 : Continuously update frequency offset filter.

4 MODULATION_MODE 0 R/W Set one of two RF modulation modes for RX / TX

0 : IEEE 802.15.4 compliant mode 1 : Reversed phase, non-IEEE compliant (could be used to set up a system which will not receive 802.15.4 packets) 3:2 TX_MODE[1:0] 0 R/W Set test modes for TX 0 : Buffered mode, use TXFIFO (normal operation) 1 : Serial mode, use transmit data on serial interface, infinite transmission. For lab testing only. 2 : TXFIFO looping ignore underflow in TXFIFO and read cyclic, infinite transmission. For lab testing only. 3 : Send random data from CRC, infinite transmission. For lab testing only. 1:0 RX_MODE[1:0] 0 R/W Set test mode of RX 0 : Buffered mode, use RXFIFO (normal operation) 1 : Receive serial mode, output received data on pins. Infinite RX. For lab testing only. 2 : RXFIFO looping ignore overflow in RXFIFO and write cyclic, infinite reception. For lab testing only. 3 : Reserved RSSI (0x13) - RSSI and CCA Status and Control Register Bit Field Name Reset R/W Description 15:8 CCA_THR[7:0] -32 R/W Clear Channel Assessment threshold value, signed number on 2’s complement for comparison with the RSSI. The unit is 1 dB, offset is the same as for RSSI_VAL. The CCA signal goes active when the received signal is below this value. The CCA signal is available on the CCA pin. The reset value is approximately -77 dBm. 7:0 RSSI_VAL[7:0] -128 R RSSI estimate on a logarithmic scale, signed number on 2’s complement. Unit is 1 dB, offset is described in the RSSI / Energy Detection section on page 48. The RSSI_VAL value is averaged over 8 symbol periods. The RSSI_VALID status bit may be checked to verify that the receiver has been enabled for at least 8 symbol periods. The reset value of –128 also indicates that the RSSI_VAL value is invalid.

SYNCWORD (0x14) - Sync Word Bit Field Name Reset R/W Description 15:0 SYNCWORD[15:0] 0xA70F R/W Synchronisation word. The SYNCWORD is processed from the least significant nibble (F at reset) to the most significant nibble (A at reset). SYNCWORD is used both during modulation (where 0xF’s are replaced with 0x0’s) and during demodulation (where 0xF’s are not required for frame synchronisation). In reception an implicit zero is required before the first symbol required by SYNCWORD. The reset value is compliant with IEEE 802.15.4. TXCTRL (0x15) - Transmit Control Register Bit Field Name Reset R/W Description 15:14 TXMIXBUF_CUR[1:0] 2 R/W TX mixer buffer bias current. 0: 690uA 1: 980uA 2: 1.16mA (nominal) 3: 1.44mA 13 TX_TURNAROUND 1 R/W Sets the wait time after STXON before transmission is started. 0 : 8 symbol periods (128 us) 1 : 12 symbol periods (192 us) 12:11 TXMIX_CAP_ARRAY[1:0] 0 R/W Selects varactor array settings in the transmit mixers. 10:9 TXMIX_CURRENT[1:0] 0 R/W Transmit mixers current: 0: 1.72 mA 1: 1.88 mA 2: 2.05 mA 3: 2.21 mA 8:6 PA_CURRENT[2:0] 3 R/W Current programming of the PA 0: -3 current adjustment 1: -2 current adjustment 2: -1 current adjustment 3: Nominal setting 4: +1 current adjustment 5: +2 current adjustment 6: +3 current adjustment 7: +4 current adjustment 5 - 1 W1 Reserved, write as 1. 4:0 PA_LEVEL[4:0] 31 R/W Output PA level. (~0 dBm)

RXCTRL0 (0x16) – Receive control register 0 Bit Field Name Reset R/W Description 15:14 - 0 W0 Reserved, write as 0. 13:12 RXMIXBUF_CUR[1:0] 1 R/W RX mixer buffer bias current. 0: 690uA 1: 980uA (nominal) 2: 1.16mA 3: 1.44mA 11:10 HIGH_LNA_GAIN[1:0] 0 R/W Controls current in the LNA gain compensation branch in AGC High gain mode. 0: Compensation disabled 1: 100 µA compensation current 2: 300 µA compensation current (Nominal) 3: 1000 µA compensation current 9:8 MED_LNA_GAIN[1:0] 2 R/W Controls current in the LNA gain compensation branch in AGC Med gain mode. 7:6 LOW_LNA_GAIN[1:0] 3 R/W Controls current in the LNA gain compensation branch in AGC Low gain mode 5:4 HIGH_LNA_CURRENT[1:0] 2 R/W Controls main current in the LNA in AGC High gain mode 0: 240 µA LNA current (x2) 1: 480 µA LNA current (x2) 2: 640 µA LNA current (x2) 3: 1280 µA LNA current (x2) 3:2 MED_LNA_CURRENT[1:0] 1 R/W Controls main current in the LNA in AGC Med gain mode 1:0 LOW_LNA_CURRENT[1:0] 1 R/W Controls main current in the LNA in AGC Low gain mode

RXCTRL1 (0x17) - Receive control register 1 Bit Field Name Reset R/W Description 15:14 - 0 W0 Reserved, write as 0.

13 RXBPF_LOCUR 0 R/W Controls reference bias current to RX bandpass filters:

0: 4 uA (Reset value) Use 1 instead 1: 3 uA Note: Recommended setting

12 RXBPF_MIDCUR 0 R/W Controls reference bias current to RX bandpass filters:

0: 4 uA (Default) 1: 3.5 uA 11 LOW_LOWGAIN 1 R/W LNA low gain mode setting in AGC low gain mode. 10 MED_LOWGAIN 0 R/W LNA low gain mode setting in AGC medium gain mode. 9 HIGH_HGM 1 R/W RX Mixers high gain mode setting in AGC high gain mode. 8 MED_HGM 0 R/W RX Mixers high gain mode setting in AGC medium gain mode. 7:6 LNA_CAP_ARRAY[1:0] 1 R/W Selects varactor array setting in the LNA 0: OFF 1: 0.1pF (x2) (Nominal) 2: 0.2pF (x2) 3: 0.3pF (x2) 5:4 RXMIX_TAIL[1:0] 1 R/W Control of the receiver mixers output current. 0: 12 µA 1: 16 µA (Nominal) 2: 20 µA 3: 24 µA 3:2 RXMIX_VCM[1:0] 1 R/W Controls VCM level in the mixer feedback loop 0: 8 µA mixer current 1: 12 µA mixer current (Nominal) 2: 16 µA mixer current 3: 20 µA mixer current 1:0 RXMIX_CURRENT[1:0] 2 R/W Controls current in the mixer 0: 360 µA mixer current (x2) 1: 720 µA mixer current (x2) 2: 900 µA mixer current (x2) (Nominal) 3: 1260 µA mixer current (x2)

FSCTRL (0x18) - Frequency Synthesizer Control and Status Bit Field Name Reset R/W Description 15:14 LOCK_THR[1:0] 1 R/W Number of consecutive reference clock periods with successful synchronisation windows required to indicate lock: 0: 64 1: 128 (recommended) 2: 256 3: 512

13 CAL_DONE 0 R Calibration has been performed since the last time the frequency

synthesizer was turned on.

12 CAL_RUNNING 0 R Calibration status, '1' when calibration in progress and ‘0’

otherwise.

11 LOCK_LENGTH 0 R/W Synchronisation window pulse width:

0: 2 prescaler clock periods (recommended) 1: 4 prescaler clock periods

10 LOCK_STATUS 0 R Frequency synthesizer lock status:

0 : Frequency synthesizer is out of lock 1 : Frequency synthesizer is in lock 9:0 FREQ[9:0] 357 (2405 MHz) R/W Frequency control word, controlling the RF operating frequency FC. In transmit mode, the local oscillator (LO) frequency equals FC. In receive mode, the LO frequency is 2 MHz below FC. F C = 2048 + FREQ[9:0] MHz See the Frequency and Channel Programming section on page 50 for further information.

SECCTRL0 (0x19) - Security Control Register Bit Field Name Reset R/W Description 15:10 - 0 W0 Reserved, write as 0

9 RXFIFO_PROTECTION 1 R/W Protection enable of the RXFIFO, see description in the RXFIFO

overflow section on page 33. Should be cleared if MAC level security is not used or is implemented outside CC2420.

8 SEC_CBC_HEAD 1 R/W Defines what to use for the first byte in CBC-MAC (does not

apply to CBC-MAC part of CCM): 0 : Use the first data byte as the first byte into CBC-MAC 1 : Use the length of the data to be authenticated (calculated as (the packet length field – SEC_TXL – 2) for TX or using SEC_RXL for RX) as the first byte into CBC-MAC (before the first data byte). This bit should be set high for CBC-MAC 802.15.4 inline security.

7 SEC_SAKEYSEL 1 R/W Stand Alone Key select

0 : Key 0 is used 1 : Key 1 is used

6 SEC_TXKEYSEL 1 R/W TX Key select

0 : Key 0 is used 1 : Key 1 is used

5 SEC_RXKEYSEL 0 R/W RX Key select

0 : Key 0 is used 1 : Key 1 is used 4:2 SEC_M[2:0] 1 R/W Number of bytes in authentication field for CBC-MAC, encoded as (M-2)/2 0 : Reserved 1 : 4 2 : 6 3 : 8 4 : 10 5 : 12 6 : 14 7 : 16 1:0 SEC_MODE[1:0] 0 R/W Security mode 0 : In-line security is disabled 1 : CBC-MAC 2 : CTR 3 : CCM

SECCTRL1 (0x1A) - Security Control Register Bit Field Name Reset R/W Description 15 - 0 W0 Reserved, write as 0 14:8 SEC_TXL 0 R/W Multi-purpose length byte for TX in-line security operations: CTR : Number of cleartext bytes between length byte and the first byte to be encrypted CBC/MAC : Number of cleartext bytes between length byte and the first byte to be authenticated CCM : l(a), defining the number of bytes to be authenticated but not encrypted Stand-alone : SEC_TXL has no effect 7 - 0 W0 Reserved, write as 0 6:0 SEC_RXL 0 R/W Multi-purpose length byte for RX in-line security operations: CTR : Number of cleartext bytes between length byte and the first byte to be decrypted CBC/MAC : Number of cleartext bytes between length byte and the first byte to be authenticated CCM : l(a), defining the number of bytes to be authenticated but not decrypted Stand-alone : SEC_RXL has no effect BATTMON (0x1B) – Battery Monitor Control register Bit Field Name Reset R/W Description 15:7 - 0 W0 Reserved, write as 0 6 BATTMON_OK 1 R Battery monitor comparator output, read only. BATT_OK is valid 5 us after BATTMON_EN has been asserted and BATTMON_VOLTAGE has been programmed. 0 : Power supply < Toggle Voltage 1 : Power supply > Toggle Voltage

5 BATTMON_EN 0 R/W Battery monitor enable

0 : Battery monitor is disabled 1 : Battery monitor is enabled 4:0 BATTMON_VOLTAGE [4:0] 0 R/W Battery monitor toggle voltage. The toggle voltage is given by: 72V25.1Vtoggle LTAGEBATTMON_VO−⋅=

IOCFG0 (0x1C) – I/O Configuration Register 0 Bit Field Name Reset R/W Description 15:12 - 0 W0 Reserved, write as 0 11 BCN_ACCEPT 0 R/W Accept all beacon frames when address recognition is enabled. This bit should be set when the PAN identifier programmed into CC2420 RAM is equal to 0xFFFF and cleared otherwise. This bit is don't care when MDMCTRL0.ADR_DECODE = 0. 0 : Only accept beacons with a source PAN identifier which matches the PAN identifier programmed into CC2420 RAM 1 : Accept all beacons regardless of the source PAN identifier 10 FIFO_POLARITY 0 R/W Polarity of the output signal FIFO. 0 : Polarity is active high 1 : Polarity is active low 9 FIFOP_POLARITY 0 R/W Polarity of the output signal FIFOP. 0 : Polarity is active high 1 : Polarity is active low 8 SFD_POLARITY 0 R/W Polarity of the SFD pin. 0 : Polarity is active high 1 : Polarity is active low 7 CCA_POLARITY 0 R/W Polarity of the CCA pin. 0 : Polarity is active high 1 : Polarity is active low 6:0 FIFOP_THR[6:0] 64 R/W FIFOP_THR sets the threshold in number of bytes in the RXFIFO for FIFOP to go active. IOCFG1 (0x1D) – I/O Configuration Register 1 Bit Field Name Reset R/W Description 15:13 - 0 W0 Reserved, write as 0 12:10 HSSD_SRC[2:0] 0 R/W The HSSD module is used as follows: 0: Off. 1: Output AGC status (gain setting / peak detector status / accumulator value) 2: Output ADC I and Q values. 3: Output I/Q after digital down mix and channel filtering. 4: Reserved 5: Reserved 6: Input ADC I and Q values 7: Input DAC I and Q values. The HSSD module requires that the FS is up and running as it uses CLK_PRE (~150 MHZ) to produce its ~37.5 MHz data clock and serialize its output words. 9:5 SFDMUX[4:0] 0 R/W Multiplexer setting for the SFD pin. 4:0 CCAMUX[4:0] 0 R/W Multiplexer setting for the CCA pin. MANFIDL (0x1E) - Manufacturer ID, Lower 16 Bit Bit Field Name Reset R/W Description 15:12 PARTNUM[3:0] 2 R The device part number. CC2420 has part number 0x002. 11:0 MANFID[11:0] 0x33D R Gives the JEDEC manufacturer ID. The actual manufacturer ID can be found in MANIFID[7:1], the number of continuation bytes in MANFID[11:8] and MANFID[0]=1. Chipcon's JEDEC manufacturer ID is 0x7F 0x7F 0x7F 0x9E (0x1E preceded by three continuation bytes.)

MANFIDH (0x1F) - Manufacturer ID, Upper 16 Bit Bit Field Name Reset R/W Description 15:12 VERSION[3:0] 3 R Version number. Current version is 3. Note that previous CC2420 versions will have lower reset values. 11:0 PARTNUM[15:4] 0 R The device part number. CC2420 has part number 0x002. FSMTC (0x20) - Finite state machine time constants Bit Field Name Reset R/W Description 15:13 TC_RXCHAIN2RX[2:0] 3 R/W The time in 5 us steps between the time the RX chain is enabled and the demodulator and AGC is enabled. The RX chain is started when the bandpass filter has been calibrated (after 6.5 symbol periods). 12:10 TC_SWITCH2TX[2:0] 6 R/W The time in advance the RXTX switch is set high, before enabling TX. In µs. 9:6 TC_PAON2TX[3:0] 10 R/W The time in advance the PA is powered up before enabling TX. In µs. 5:3 TC_TXEND2SWITCH[2:0] 2 R/W The time after the last chip in the packet is sent, and the TXRX switch is disabled. In µs. 2:0 TC_TXEND2PAOFF[2:0] 4 R/W The time after the last chip in the packet is sent, and the PA is set in power-down. Also the time at which the modulator is disabled. In µs.

MANAND (0x21) - Manual signal AND override register1 Bit Field Name Reset R/W Description

15 VGA_RESET_N 1 R/W The VGA_RESET_N signal is used to reset the peak detectors in

the VGA in the RX chain.

14 BIAS_PD 1 R/W Global bias power down (1)

13 BALUN_CTRL 1 R/W The BALUN_CTRL signal controls whether the PA should

receive its required external biasing (1) or not (0) by controlling the RX/TX output switch.

12 RXTX 1 R/W RXTX signal: controls whether the LO buffers (0) or PA buffers

(1) should be used. 11 PRE_PD 1 R/W Powerdown of prescaler. 10 PA_N_PD 1 R/W Powerdown of PA (negative path). 9 PA_P_PD 1 R/W Powerdown of PA (positive path). When PA_N_PD=1 and PA_P_PD=1 the up-conversion mixers are in powerdown. 8 DAC_LPF_PD 1 R/W Powerdown of TX DACs.

7 XOSC16M_PD 1 R/W

6 RXBPF_CAL_PD 1 R/W Powerdown control of complex bandpass receive filter calibration

oscillator. 5 CHP_PD 1 R/W Powerdown control of charge pump. 4 FS_PD 1 R/W Powerdown control of VCO, I/Q generator, LO buffers. 3 ADC_PD 1 R/W Powerdown control of the ADCs. 2 VGA_PD 1 R/W Powerdown control of the VGA. 1 RXBPF_PD 1 R/W Powerdown control of complex bandpass receive filter.

0 LNAMIX_PD 1 R/W Powerdown control of LNA, down-conversion mixers and front-

end bias. 1 For some important signals the value used by analog and digital modules can be overridden manually. This is done as follows for the hypothetical important signal IS: IS_USED = (IS * IS_AND_MASK) + IS_OR_MASK, using boolean notation. The AND-mask and OR-mask for the important signals listed resides in the MANAND and MANOR registers, respectively. Examples:

• Writing 0xFFFE to MANAND and 0x0000 to MANOR will force LNAMIX_PD ≡0 whereas all other signals will be unaffected.
• Writing 0xFFFF to MANAND and 0x0001 to MANOR will force LNAMIX_PD ≡1 whereas all other signals will be unaffected.

MANOR (0x22) - Manual signal OR override register Bit Field Name Reset R/W Description

15 VGA_RESET_N 0 R/W The VGA_RESET_N signal is used to reset the peak detectors in

the VGA in the RX chain.

14 BIAS_PD 0 R/W Global Bias power down (1)

13 BALUN_CTRL 0 R/W The BALUN_CTRL signal controls whether the PA should receive

its required external biasing (1) or not (0) by controlling the RX/TX output switch.

12 RXTX 0 R/W RXTX signal: controls whether the LO buffers (0) or PA buffers

(1) should be used. 11 PRE_PD 0 R/W Powerdown of prescaler. 10 PA_N_PD 0 R/W Powerdown of PA (negative path). 9 PA_P_PD 0 R/W Powerdown of PA (positive path). When PA_N_PD=1 and PA_P_PD=1 the up-conversion mixers are in powerdown. 8 DAC_LPF_PD 0 R/W Powerdown of TX DACs.

7 XOSC16M_PD 0

6 RXBPF_CAL_PD 0 R/W Powerdown control of complex bandpass receive filter calibration

oscillator. 5 CHP_PD 0 R/W Powerdown control of charge pump. 4 FS_PD 0 R/W Powerdown control of VCO, I/Q generator, LO buffers. 3 ADC_PD 0 R/W Powerdown control of the ADCs. 2 VGA_PD 0 R/W Powerdown control of the VGA. 1 RXBPF_PD 0 R/W Powerdown control of complex bandpass receive filter.

0 LNAMIX_PD 0 R/W Powerdown control of LNA, down-conversion mixers and front-

end bias. AGCCTRL (0x23) - AGC Control Bit Field Name Reset R/W Description 15:12 - 0 W0 Reserved, write as 0 11 VGA_GAIN_OE 0 R/W Use the VGA_GAIN value during RX instead of the AGC value. 10:4 VGA_GAIN [6:0] 0x7F R/W When written, VGA manual gain override value; when read, the currently used VGA gain setting. 3:2 LNAMIX_GAINMODE_O [1:0]

0 R/W LNA / Mixer Gain mode override setting

0 : Gain mode is set by AGC algorithm 1 : Gain mode is always low-gain 2 : Gain mode is always med-gain 3 : Gain mode is always high-gain 1:0 LNAMIX_GAINMODE [1:0]

3 R Status bit, defining the currently selected gain mode selected by

the AGC or overridden by the LNAMIX_GAINMODE_O setting.

AGCTST0 (0x24) - AGC Test Register 0 Bit Field Name Reset R/W Description 15:12 LNAMIX_HYST[3:0] 3 R/W Hysteresis on the switching between different RF front-end gain modes, defined in 2 dB steps 11:6 LNAMIX_THR_H[5:0] 25 R/W Threshold for switching between medium and high RF front- end gain mode, defined in 2 dB steps 5:0 LNAMIX_THR_L[5:0] 9 R/W Threshold for switching between low and medium RF front-end gain mode, defined in 2 dB steps AGCTST1 (0x25) - AGC Test Register 1 Bit Field Name Reset R/W Description 15 - 0 W0 Reserved, write as 0

14 AGC_BLANK_MODE 0 R/W Set the VGA blanking mode when switching out a gain stage

When VGA_GAIN_OE = 0: 0 : Blanking is performed when the AGC algorithm switches out one or more 14dB gain stages. 1 : Blanking is never performed. When VGA_GAIN_OE = 1: Blanking is performed when AGC_BLANK_MODE=1

13 PEAKDET_CUR_BOOST 0 R/W Doubles the bias current in the peak-detectors in-between the

VGA stages when set. 12:11 AGC_SETTLE_WAIT[1:0] 1 R/W Timing for AGC to wait for analog gain to settle. 10:8 AGC_PEAK_DET_MODE [2:0]

0 R/W Sets the AGC mode for use of the VGA peak detectors:

Bit 2 : Digital ADC peak detector enable / disable Bit 1 : Analog fixed stages peak detector enable / disable Bit 0 : Analog variable gain stage peak detector enable / disable 7:6 AGC_WIN_SIZE[1:0] 1 R/W Window size for the accumulate and dump function in the AGC. 0 : 8 samples 1 : 16 samples 2 : 32 samples 3 : 64 samples 5:0 AGC_REF[5:0] 20 R/W Target value for the AGC control loop, given in 2 dB steps. Reset value corresponds to approximately 25% of the ADC dynamic range in reception. AGCTST2 (0x26) - AGC Test Register 2 Bit Field Name Reset R/W Description 15:10 - 0 W0 Reserved, write as 0 9:5 MED2HIGHGAIN[4:0] 9 R/W MED2HIGHGAIN sets the difference in the receiver LNA/MIXER gain from medium gain mode to high gain mode, used by the AGC for setting the correct front-end gain mode. 4:0 LOW2MEDGAIN[4:0] 10 R/W LOW2MEDGAIN sets the difference in the receiver LNA/MIXER gain from low gain mode to medium gain mode, used by the AGC for setting the correct front-end gain mode.

FSTST0 (0x27) - Frequency Synthesizer Test Register 0 Bit Field Name Reset R/W Description 15:12 - 0 W0 Reserved, write as 0

11 VCO_ARRAY_SETTLE_LONG 0 R/W When '1' this control bit doubles the time allowed for VCO

settling during VCO calibration. 10 VCO_ARRAY_OE 0 R/W VCO array manual override enable. 9:5 VCO_ARRAY_O[4:0] 16 R/W VCO array override value. 4:0 VCO_ARRAY_RES[4:0] 16 R The VCO array result holds the register content of the most recent calibration. FSTST1 (0x28) - Frequency Synthesizer Test Register 1 Bit Field Name Reset R/W Description

15 VCO_TX_NOCAL 0 R/W 0 : VCO calibration is always performed when going to RX or

when going to TX. 1 : VCO calibration is only performed when going to RX or when using the STXCAL command strobe

14 VCO_ARRAY_CAL_LONG 1 R/W When ‘1’ this control bit doubles the time allowed for VCO

frequency measurements during VCO calibration. 0 : PLL Calibration time is 37 us 1 : PLL Calibration time is 57 us 13:10 VCO_CURRENT_REF[3:0] 4 R/W The value of the reference current calibrated against during VCO calibration. 9:4 VCO_CURRENT_K[5:0] 0 R/W VCO current calibration constant. (Current B override value when FSTST2.VCO_CURRENT_OE=1.)

3 VC_DAC_EN 0 R/W Controls the source of the VCO VC node in normal operation

(TOPTST.VC_IN_TEST_EN=0): 0: Loop filter (closed loop PLL) 1: VC DAC (open loop PLL) 2:0 VC_DAC_VAL[2:0] 2 R/W VC DAC output value FSTST2 (0x29) - Frequency Synthesizer Test Register 2 Bit Field Name Reset R/W Description 15 - 0 W0 Reserved, write as 0. 14:13 VCO_CURCAL_SPEED[1:0] 0 R/W VCO current calibration speed: 0: Normal 1: Double speed 2: Half speed 3: Undefined. 12 VCO_CURRENT_OE 0 R/W VCO current manual override enable. 11:6 VCO_CURRENT_O[5:0] 24 R/W VCO current override value (current A). 5:0 VCO_CURRENT_RES[5:0] 32 R The VCO current result holds the register content of the most recent calibration.

FSTST3 (0x2A) - Frequency Synthesizer Test Register 3 Bit Field Name Reset R/W Description 15 CHP_CAL_DISABLE 1 R/W Disable charge pump during VCO calibration when set.

14 CHP_CURRENT_OE 0 R/W Charge pump current override enable

0 : Charge pump current set by calibration 1 : Charge pump current set by START_CHP_CURRENT

13 CHP_TEST_UP 0 R/W Forces the CHP to output "up" current when set

12 CHP_TEST_DN 0 R/W Forces the CHP to output "down" current when set

11 CHP_DISABLE 0 R/W Set to manually disable charge pump by masking the up and

down pulses from the phase-detector.

10 PD_DELAY 0 R/W Selects short or long reset delay in phase detector:

0: Short reset delay 1: Long reset delay 9:8 CHP_STEP_PERIOD[1:0] 2 R/W The charge pump current value step period: 0: 0.25 us 1: 0.5 us 2: 1 us 3: 4 us 7:4 STOP_CHP_CURRENT[3:0] 13 R/W The charge pump current to stop at after the current is stepped down from START_CHP_CURRENT after VCO calibration is complete. The current is stepped down periodically with intervals as defined in CHP_STEP_PERIOD. 3:0 START_CHP_CURRENT[3:0] 13 R/W The charge pump current to start with after VCO calibration is complete. The current is then stepped down periodically to the value STOP_CHP_CURRENT with intervals as defined in CHP_STEP_PERIOD. Also used for overriding the charge pump current when CHP_CURRENT_OE=’1’ RXBPFTST (0x2B) - Receiver Bandpass Filters Test Register Bit Field Name Reset R/W Description 15 - 0 W0 Reserved, write as 0. 14 RXBPF_CAP_OE 0 R/W RX bandpass filter capacitance calibration override enable. 13:7 RXBPF_CAP_O[6:0] 0 R/W RX bandpass filter capacitance calibration override value. 6:0 RXBPF_CAP_RES[6:0] 0 R RX bandpass filter capacitance calibration result. 0: Minimum capacitance in the feedback. 1: Second smallest capacitance setting. 127: Maximum capacitance in the feedback. FSMSTATE (0x2C) - Finite state machine information Bit Field Name Reset R/W Description 15:6 - 0 W0 Reserved, write as 0. 5:0 FSM_CUR_STATE[5:0] 0 R Provides the current state of the FIFO and Frame Control (FFCTRL) finite state machine. See the Radio control state machine section on page 43 for details.

ADCTST (0x2D) - ADC Test Register Bit Field Name Reset R/W Description

15 ADC_CLOCK_DISABLE 0 R/W ADC Clock Disable

0 : Clock enabled when ADC enabled 1 : Clock disabled, even if ADC is enabled 14:8 ADC_I[6:0] 0 R Read the current ADC I-branch value. 7 - 0 W0 Reserved, write as 0. 6:0 ADC_Q[6:0] 0 R Read the current ADC Q-branch value. DACTST (0x2E) - DAC Test Register Bit Field Name Reset R/W Description 15 - 0 W0 Reserved, write as 0. 14:12 DAC_SRC[2:0] 0 R/W The TX DACs data source is selected by DAC_SRC according to: 0: Normal operation (from modulator). 1: The DAC_I_O and DAC_Q_O override values below.- 2: From ADC, most significant bits 3: I/Q after digital down mixing and channel filtering. 4: Full-spectrum White Noise (from CRC) 5: From ADC, least significant bits 6: RSSI / Cordic Magnitude Output 7: HSSD module. This feature will often require the DACs to be manually turned on in MANOR and TOPTST.ATESTMOD_MODE=4. 11:6 DAC_I_O[5:0] 0 R/W I-branch DAC override value. 5:0 DAC_Q_O[5:0] 0 R/W Q-branch DAC override value.

TOPTST (0x2F) - Top Level Test Register Bit Field Name Reset R/W Description 15:8 - 0 W0 Reserved, write as 0.

7 RAM_BIST_RUN 0 R/W Enable BIST of the RAM

0 : RAM BIST disabled, normal operation 1 : RAM BIST Enabled. Result output to pin, as set in IOCFG1. 6 TEST_BATTMON_EN 0 R/W Enable test output of the battery monitor.

5 VC_IN_TEST_EN 0 R/W When ATESTMOD_MODE=7 this controls whether the ATEST2

in is used to output the VC node voltage (0) or to control the VC node voltage (1). 4 ATESTMOD_PD 1 R/W Powerdown of analog test module. 0 : Power up 1 : Power down 3:0 ATESTMOD_MODE[3:0] 0 When ATESTMOD_PD=0, the function of the analog test module is as follows: 0: Outputs “I” (ATEST1) and “Q” (ATEST2) from RxMIX. 1: Inputs “I” (ATEST2) and “Q” (ATEST1) to BPF. 2: Outputs “I” (ATEST1) and “Q” (ATEST2) from VGA. 3: Inputs “I” (ATEST2) and “Q” (ATEST1) to ADC. 4: Outputs “I” (ATEST1) and “Q” (ATEST2) from LPF. 5: Inputs “I” (ATEST2) and “Q” (ATEST1) to TxMIX. 6: Outputs “P” (ATEST1) and “N” (ATEST2) from Prescaler. Must be terminated externally. 7: Connects TX IF to RX IF and simultaneously the ATEST1 pin to the internal VC node (see VC_IN_TEST_EN). 8. Connect ATEST1 (input) to ATEST2 (output) through single2diff and diff2single buffers, used for measurements on the test-interface RESERVED (0x30) - Reserved register containing spare control and status bits Bit Field Name Reset R/W Description 15:0 RES[15:0] 0 R/W Reserved for future use TXFIFO (0x3E) – Transmit FIFO Byte register Bit Field Name Reset R/W Description 7:0 TXFIFO[7:0] 0 W Transmit FIFO byte register, write only. Reading the TXFIFO is only possible using RAM read. Note that the crystal oscillator must be running for writing to the TXFIFO. RXFIFO (0x3F) – Receive FIFO Byte register Bit Field Name Reset R/W Description 7:0 RXFIFO[7:0] 0 R/W Receive FIFO byte register, read / write. Note that the crystal oscillator must be running for accessing the RXFIFO.

38 Test Output Signals

Table 12 and Table 13 below.

0 CCA Normal operation

1 ADC_Q[0] ADC, Q-branch, LSB used for random number generation

2 DEMOD_RESYNC_LATE High one 16 MHz cl ock cycle each time the demodulator

4 MOD_CHIPCLK Chip rate cl ock signal during transmission

5 MOD_SERIAL_CLK Bit rate cl ock signal during transmission

6 FFCTRL_FS_PD Frequency synthesiz er power down, active high

7 FFCTRL_ADC_PD ADC power down, active high

8 FFCTRL_VGA_PD VGA power down, active high

9 FFCTRL_RXBPF_PD Receiver bandpass filter power down, active high

10 FFCTRL_LNAMIX_PD Receiver LNA / Mixer power down, active high

11 FFCTRL_PA_P_PD Power amplifier power down, active high

12 AGC_UPDATE High one 16 MHz clock cycl e each time the AGC updates its gain

13 VGA_PEAK_DET[1] VGA Peak detector, gain stage 1

14 VGA_PEAK_DET[3] VGA Peak detector, gain stage 3

15 AGC_LNAMIX_GAINMODE[1] RF re ceiver front-end gain mode, bit 1

16 AGC_VGA_GAIN[1] VGA gain setting, bit 1

17 VGA_RESET_N VGA peak-detecto r reset sign, active low.

23 CLK_8M 8 MHz clock signal output

24 XOSC16M_STABLE 16 MHz crystal oscillator stab ilised, same as the status bit in Table

25 FSDIG_FREF Frequency synthesiz er, 4 MHz reference signal

26 FSDIG_FPLL Frequency synthes izer, 4 MHz divided signal

27 FSDIG_LOCK_WINDOW Frequency synthesizer, lock window

28 WINDOW_SYNC Frequency synthesizer, synchronized lock window

29 CLK_ADC ADC clock signal 1

30 ZERO Low

31 ONE High

Table 12. CCA test signal select table

0 SFD Normal operation

1 ADC_I[0] ADC, I-branch, LSB used for random number generation

2 DEMOD_RESYNCH_EARLY High one 16 MHz clock cycle each time the demodulator

4 MOD_CHIP Chip rate dat a signal during transmission

5 MOD_SERIAL_DATA_OUT Bit rate data signal during transmission

12 VGA_PEAK_DET[0] VGA Peak detector, gain stage 0

13 VGA_PEAK_DET[2] VGA Peak detector, gain stage 2

14 VGA_PEAK_DET[4] VGA Peak detector, gain stage 4

15 AGC_LNAMIX_GAINMODE[0] RF re ceiver front-end gain mode, bit 0

16 AGC_VGA_GAIN[0] VGA gain setting, bit 0

17 RXBPF_CAL_CLK Receiver bandpa ss filter calibration clock

24 PD_F_COMP Frequency synthesizer frequency comparator value

29 CLK_ADC_DIG ADC clock signal 2

Table 13. SFD test signal select table

Note: The figure is an illustration only and not to scale. Quad Leadless Package (QLP) D D1 E E1 e b L D2 E2 QLP 48 Min Max 6.9 7.0 7.1 6.65 6.75 6.85 6.9 7.0 7.1 6.65 6.75 6.85 0.5 0.18 0.30 0.3 0.4 0.5 5.05 5.10 5.15 5.05 5.10 5.15 The overall packet height is 0.85 +/- 0.05 All dimensions in mm The package is compliant to JEDEC standard MO-220.

40 Recommended layout for package (QLP 48)

Note: The figure is an illustration only and not to scale. There are nine 14 mil diameter via holes distributed symmetrically in the gr ound pad under the package. See also the CC2420 EM reference design.

40.1 Package thermal properties

Air velocity [m/s] 0 Rth,j-a [K/W] 25.6

40.2 Soldering information

Recommended soldering profile is according to IPC/JEDEC J-STD-020C.

40.3 Plastic tube specification

QLP 7x7mm antistatic tube. Tube Specification Package Tube Width Tube Height Tube Length Units per Tube

40.4 Carrier tape and reel specification

Carrier tape and reel is in accordance with EIA Specification 481. Tape and Reel Specification Package Tape Width Component Pitch Hole Pitch Reel Diameter Units per Reel QLP 48 16 mm 12 mm 4 mm 13 inch 4000 Chipcon Part Number TI Part Number Description Minimum Order Quantity (MOQ) CC2420-RTB1 CC2420RTC Single-chip RF Tr ansceiver. CC2420, QLP48 package, RoHS compliant Pb-free assembly in tubes with 43 pcs per tube. 43 (tube) CC2420-RTR1 CC2420RTCR Single-chip RF Tr ansceiver.. CC2420, QLP48 package, RoHS compliant Pb-free assembly, T&R with 4000 pcs per reel. 4000 (tape and reel) CC2420Z-RTB1 CC2420ZRTC Single-chip RF Transce iver including royalty for using TI’s ZigBee Software Stack, Z-Stack™, in an end product. CC2420, QLP48 package, RoHS compliant Pb-free assembly in tubes with 43 pcs per tube. 43 (tube) CC2420Z-RTR1 CC2420ZRTCR Single-chip RF Tran sceiver including royalty for using TI’s ZigBee Software Stack, Z-Stack™, in an end product. CC2420, QLP48 package, RoHS compliant Pb-free assembly, T&R with 4000 pcs per reel 4000 (tape and reel) CC2420ZDK CC2420ZDK CC2420ZDK ZigBee Development Kit 1 CC2420ZDK-Pro CC2420ZDK-Pro CC2420ZDK-P ro ZigBee Development Kit Pro 1 CC2420DBK CC2420DBK CC2420DBK Demonstration Board Kit 1 CC2420DK CC2420DK CC2420DK Development Kit 1 CC2420EMK CC2420EMK CC2420DBK Evaluation Module Kit 1

42 General Information

42.1 Document History

Revision Date Description/Changes SWRS041b 2007-03-19 Slightly changed optimum load impedanc e on Page 9 and 19 to better describe the Application circuit. SWRS041a 2006-12-18 Updated ordering information. Updated address information. Typical data latency changed from 2 to 3 us. Updates reflecting the programmable polarity of FIFO, FIFOP, SFD and CCA pins. Clarification relating to VREG_EN as digital input. BATT_OK changed to BATTMON_OK for consistency. MANFIDH.VERSION register, reset value changed to ”current version is 3”. Added reset values for several registers. Some typographical changes. Removed Chipcon specific Disclaimer, Trademarks and Life Support Policy sections. SWRS041 (1.4) RTB1 and CC2420Z-RTR1 respectively. 1.3 2005-10-03 Important: New recommended setting for RXBPF_LOCUR in RXCTRL1 (0x17) use 1 instead of reset value 0. Updated address information. Added new balun circuit with transmission lines in section Application Circuit. Updated electrical specifications with measured data on CC2420 EM with new balun. Updated values and figure for suggested application circuit with folded dipole antenna. Corrected values for capacitors in Table 2, discrete balun. Added data latency figure in receiver specification. Updated crystal oscillator start up time. Updated PLL loop filter bandwidth. Updated adjacent channel rejection figures. Updated current consumption for RX mode. Typographical errors corrected in text and figures. Removed comment about tuning capacitor for crystal oscillator. Added statement that RAM access shall not be used for FIFO access. Added more details about RSSI. Clarified the interpretation of a programmed synchronisation word. Updated purchasing information. Updated soldering standard. Added chapter numbering and split table for electrical specifications for readability. Gathered and added information related to pin configurations in section 13. Included TX_UNDERFLOW and RX_UNDERFLOW in state diagram. Disclaimer updated to include Z-stack TM information. Product status changed to “Full Production”.

Revision Date Description/Changes 1.2 2004-06-09 Output power range: 24 dB (was 40 dB). Deleted option for single ended external PA. Adjacent channel rejection corrected to 46 dB for + 5MHz (was 39 dB), 39 dB for –5 MHz (was 46 dB) 58 dB for +10 MHz (was 53 dB) and 55 dB for-10 MHz (was 57 dB). “image channel” deleted in text for In band spurious reception. Revision for reference [1] updated. CSMA-CA added to abbreviations. Schematic view of the IEEE 802.15.4 Frame Format corrected, address field 0 to 20 bits. Changed blocking specifications to relate to EN 300 440 class 2. Updated addresses for Chipcon offices. Added section Operating Conditions. Section RAM access: A6:0 (LSB). IOCFG0.BCN_ACCEPT bit added and described in section Address recognition and the IOCFG0 register. The previous IDLE mode has been renamed to power down to be consistent with other Chipcon data sheets. Three power modes defined: Voltage regulator off (OFF), Power down (PD) (Voltage regulator enabled), IDLE (XOSC running) and used throughout the document. Default TXMIXBUF_CUR[1:0] in table for TXCTRL set to 2. Added information: compliance with EN 300 328 og EN 300 440 (Class 2). Added more information about FIFOP in section Receive mode. Removed text about SO programmable pull up from entire document. In Voltage regulator section of Electrical Specifications: voltage regulator may only supply CC2420. MANFIDH.VERSION register, changed to ”current version is 2”. Included package height in package drawing. Included layout drawing for package. Power supply pins defined clearer in Absolute maximum ratings. Third harmonic level corrected to –51dBm in Electrical specifications, second harmonic to –37dBm. Table with Crystal oscillator component values corrected. Link to reference [3] corrected. Corrected spelling grammar and references to tables and figures. Figure showing SmartRF Studio user interface included. Added figure to describe pin activity during RXFIFO read out. Added description on how to connect pins when not using internal regulator. 1.1 2004-03-22 Application ci rcuits: Pin 20 and pin 37 connected to 1.8 V from VREG_OUT. IOCFG0.SO_PULLUP deleted. Added document history table. 1.0 2003-11-17 Initial release.

42.2 Product Status Definitions

Data Sheet Identification Product Status Definition Advance Information Planned or Under Development This data sheet contains the design specifications for product development. Specifications may change in any manner without notice. Preliminary Engineering Samples and First Production This data sheet contains preliminary data, and supplementary data will be published at a later date. Chipcon reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. No Identification Noted Full Production This dat a sheet contains the final specifications. Chipcon reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. Obsolete Not In Production This data sheet contains specifications on a product that has been discontinued by Chipcon. The data sheet is printed for reference information only.

43 Address Information

Texas Instruments Norway AS Gaustadalléen 21 N-0349 Oslo NORWAY Tel: +47 22 95 85 44 Fax: +47 22 95 85 46 Web site: http://www.ti.com/lpwrf

44 TI Worldwide Technical Support

TI Semiconductor Product Information Center Home Page: support.ti.com TI Semiconductor KnowledgeBase Home Page: support.ti.com/sc/knowledgebase Product Information Centers Americas Phone: +1(972) 644-5580 Fax: +1(972) 927-6377 Internet/Email: support.ti.com/sc/pic/americas.htm Europe, Middle East and Africa Phone: Belgium (English) +32 (0) 27 45 54 32 Finland (English) +358 (0) 9 25173948 France +33 (0) 1 30 70 11 64 Germany +49 (0) 8161 80 33 11 Israel (English) 180 949 0107 Italy 800 79 11 37 Netherlands (English) +31 (0) 546 87 95 45 Russia +7 (0) 95 363 4824 Spain +34 902 35 40 28 Sweden (English) +46 (0) 8587 555 22 United Kingdom +44 (0) 1604 66 33 99 Fax: +49 (0) 8161 80 2045 Internet: support.ti.com/sc/pic/euro.htm Japan Fax International +81-3-3344-5317 Domestic 0120-81-0036 Internet/Email International support.ti .com/sc/pic/japan.htm Domestic www.tij.co.jp/pic

Phone International +886-2-23786800 Domestic Toll-Free Number Australia 1-800-999-084 China 800-820-8682 Hong Kong 800-96-5941 India +91-80-51381665 (Toll) Indonesia 001-803-8861-1006 Korea 080-551-2804 Malaysia 1-800-80-3973 New Zealand 0800-446-934 Philippines 1-800-765-7404 Singapore 800-886-1028 Taiwan 0800-006800 Thailand 001-800-886-0010 Fax +886-2-2378-6808 Email tiasia@ti.com or ti-china@ti.com Internet support.ti.com/sc/pic/asia.htm © 2007, Texas Instruments. All rights reserved.

*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) (mm) W (mm) Pin1 Quadrant PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 Pack Materials-Page 1

*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) CC2420RTCR VQFN RTC 48 2500 336.6 336.6 28.6 PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 Pack Materials-Page 2

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