AT25DF321

AT25DF321_09 ATMEL

Document overview

• Manufacturer or author: Provided By digicamel.com
• PDF pages: 37

Technical content

Features

• Single 2.7V - 3.6V Supply
• Serial Peripheral Interface (SPI) Compatible – Supports SPI Modes 0 and 3
• 70 MHz Maximum Clock Frequency
• Flexible, Uniform Erase Architecture – 4-Kbyte Blocks – 32-Kbyte Blocks – 64-Kbyte Blocks – Full Chip Erase
• Individual Sector Protection with Global Protect/Unprotect Feature – Sixty-Four 64-Kbyte Physical Sectors
• Hardware Controlled Locking of Protected Sectors
• Flexible Programming – Byte/Page Program (1 to 256 Bytes)
• Automatic Checking and Reporting of Erase/Program Failures
• JEDEC Standard Manufacturer and Device ID Read Methodology
• Low Power Dissipation – 7 mA Active Read Current (Typical) – 15 µA Deep Power-Down Current (Typical)
• Endurance: 100,000 Program/Erase Cycles
• Data Retention: 20 Years
• Complies with Full Industrial Temperature Range
• Industry Standard Green (Pb/Halide-free/RoHS Compliant) Package Options – 8-lead SOIC (200-mil wide) – 16-lead SOIC (300-mil wide) 1. Description The AT25DF321 is a serial interface Flash memory device designed for use in a wide variety of high-volume consumer based applications in which program code is shad- owed from Flash memory into embedded or ex ternal RAM for execution. The flexible erase architecture of the AT25DF321, with it s erase granularity as small as 4-Kbytes, makes it ideal for data storage as well, eliminating the need for additional data storage EEPROM devices. The physical sectoring and the erase block sizes of the AT25DF321 have been opti- mized to meet the needs of today's code and data storage applications. By optimizing the size of the physical sectors and eras e blocks, the memory space can be used much more efficiently. Because certai n code modules and data storage segments must reside by themselves in their own protected sectors, the wasted and unused memory space that occurs with large sectored and large block erase Flash memory devices can be greatly reduced. This increased memory space efficiency allows addi- tional code routines and data storage segments to be added while still maintaining the same overall device density. 32-megabit 2.7-volt Minimum SPI Serial Flash Memory AT25DF321 3669B–DFLASH–6/09

3669B–DFLASH–6/09 AT25DF321 The AT25DF321 also offers a sophisticated meth od for protecting individual sectors against erroneous or malicious program and erase operations. By providing the ability to individually pro- tect and unprotect sectors, a system can unprotect a specific sector to modify its contents while keeping the remaining sectors of the memory array securely protected. This is useful in applica- tions where program code is patched or updated on a subroutine or module basis, or in applications where data storage segments need to be modified without running the risk of errant modifications to the program code segments. In addition to individual sector protection capabili- ties, the AT25DF321 incorporates Global Protec t and Global Unprotect features that allow the entire memory array to be either protected or unprotected all at once. This reduces overhead during the manufacturing process since sectors do not have to be unprotected one-by-one prior to initial programming. Specifically designed for use in 3-volt system s, the AT25DF321 supports read, program, and erase operations with a supply voltage range of 2.7V to 3.6V. No separate voltage is required for programming and erasing.

3669B–DFLASH–6/09 AT25DF321 2. Pin Descriptions and Pinouts Table 2-1. Pin Descriptions Symbol Name and Function Asserted State Type CS CHIP SELECT: Asserting the CS pin selects the device. When the CS pin is deasserted, the device will be deselected and normally be placed in standby mode (not Deep Power-Down mode), and the SO pin will be in a high-impedance state. When the device is deselected, data will not be accepted on the SI pin. A high-to-low transition on the CS pin is required to start an operation, and a low-to-high transition is required to end an operation. When ending an internally self-timed operation such as a program or erase cycle, the device will not enter the standby mode until the completion of the operation. Low Input SCK SERIAL CLOCK: This pin is used to provide a clock to the device and is used to control the flow of data to and from the device. Command, address, and input data present on the SI pin is always latched on the rising edge of SCK, while output data on the SO pin is always clocked out on the falling edge of SCK. Input SI SERIAL INPUT: The SI pin is used to shift data into the device. The SI pin is used for all data input including command and address sequences. Data on the SI pin is always latched on the rising edge of SCK. Input SO SERIAL OUTPUT: The SO pin is used to shift data out from the device. Data on the SO pin is always clocked out on the falling edge of SCK. Output WP WRITE PROTECT: The WP pin controls the hardware locking feature of the device. Please refer to “Protection Commands and Features” on page 12 for more details on protection features and the WP pin. The WP pin is internally pulled-high and may be left floating if hardware controlled protection will not be used. However, it is recommended that the WP pin also be externally connected to VCC whenever possible. Low Input HOLD HOLD: The HOLD pin is used to temporarily pause serial communication without deselecting or resetting the device. While the HOLD pin is asserted, transitions on the SCK pin and data on the SI pin will be ignored, and the SO pin will be in a high-impedance state. The CS pin must be asserted, and the SCK pin must be in the low state in order for a Hold condition to start. A Hold condition pauses serial communication only and does not have an effect on internally self-timed operations such as a program or erase cycle. Please refer to “Hold” on page 27 for additional details on the Hold operation. The HOLD pin is internally pulled-high and may be left floating if the Hold function will not be used. However, it is recommended that the HOLD pin also be externally connected to VCC whenever possible. Low Input VCC DEVICE POWER SUPPLY: The VCC pin is used to supply the source voltage to the device. Operations at invalid VCC voltages may produce spurious results and should not be attempted. Power GND GROUND: The ground reference for the power supply. GND should be connected to the system ground. Power

3669B–DFLASH–6/09 AT25DF321 3. Block Diagram 4. Memory Array To provide the greatest flexibility, the memory array of the AT25DF321 can be erased in four lev- els of granularity including a full chip erase. In addition, the array has been divided into physical sectors of uniform size, of which each sector can be individually protected from program and erase operations. The size of the physical sectors is optimized for both code and data storage applications, allowing both code and data segments to reside in their own isolated regions. Figure 4-1 on page 5 illustrates the breakdown of each erase level as well as the break- down of each physical sector. Figure 2-1. 8-SOIC Top View Figure 2-2. 16-SOIC Top View CS SO WP GND VCC HOLD SCK SI HOLD VCC NC NC NC NC CS SO SCK SI NC NC NC NC GND WP FLASH MEMORY ARRAY Y -GATING CS SCK SO SI Y -DECODER ADDRESS LATCH X-DECODER I/O BUFFERS AND LATCHES CONTROL AND PROTECTION LOGIC SRAM DATA BUFFER WP INTERFACE CONTROL AND LOGIC HOLD

3669B–DFLASH–6/09 AT25DF321 Figure 4-1. Memory Architecture Diagram 4KB 3FFFFFh – 3FF000h 256 Bytes 3FFFFFh – 3FFF00h 4KB 3FEFFFh – 3FE000h 256 Bytes 3FFEFFh – 3FFE00h 4KB 3FDFFFh – 3FD000h 256 Bytes 3FFDFFh – 3FFD00h 4KB 3FCFFFh – 3FC000h 256 Bytes 3FFCFFh – 3FFC00h 4KB 3FBFFFh – 3FB000h 256 Bytes 3FFBFFh – 3FFB00h 4KB 3FAFFFh – 3FA000h 256 Bytes 3FFAFFh – 3FFA00h 4KB 3F9FFFh – 3F9000h 256 Bytes 3FF9FFh – 3FF900h 4KB 3F8FFFh – 3F8000h 256 Bytes 3FF8FFh – 3FF800h 4KB 3F7FFFh – 3F7000h 256 Bytes 3FF7FFh – 3FF700h 4KB 3F6FFFh – 3F6000h 256 Bytes 3FF6FFh – 3FF600h 4KB 3F5FFFh – 3F5000h 256 Bytes 3FF5FFh – 3FF500h 4KB 3F4FFFh – 3F4000h 256 Bytes 3FF4FFh – 3FF400h 4KB 3F3FFFh – 3F3000h 256 Bytes 3FF3FFh – 3FF300h 4KB 3F2FFFh – 3F2000h 256 Bytes 3FF2FFh – 3FF200h 4KB 3F1FFFh – 3F1000h 256 Bytes 3FF1FFh – 3FF100h 4KB 3F0FFFh – 3F0000h 256 Bytes 3FF0FFh – 3FF000h 4KB 3EFFFFh – 3EF000h 256 Bytes 3FEFFFh – 3FEF00h 4KB 3EEFFFh – 3EE000h 256 Bytes 3FEEFFh – 3FEE00h 4KB 3EDFFFh – 3ED000h 256 Bytes 3FEDFFh – 3FED00h 4KB 3ECFFFh – 3EC000h 256 Bytes 3FECFFh – 3FEC00h 4KB 3EBFFFh – 3EB000h 256 Bytes 3FEBFFh – 3FEB00h 4KB 3EAFFFh – 3EA000h 256 Bytes 3FEAFFh – 3FEA00h 4KB 3E9FFFh – 3E9000h 256 Bytes 3FE9FFh – 3FE900h 4KB 3E8FFFh – 3E8000h 256 Bytes 3FE8FFh – 3FE800h 4KB 3E7FFFh – 3E7000h 4KB 3E6FFFh – 3E6000h 4KB 3E5FFFh – 3E5000h 4KB 3E4FFFh – 3E4000h 256 Bytes 0017FFh – 001700h 4KB 3E3FFFh – 3E3000h 256 Bytes 0016FFh – 001600h 4KB 3E2FFFh – 3E2000h 256 Bytes 0015FFh – 001500h 4KB 3E1FFFh – 3E1000h 256 Bytes 0014FFh – 001400h 4KB 3E0FFFh – 3E0000h 256 Bytes 0013FFh – 001300h

256 Bytes 0012FFh – 001200h

256 Bytes 0011FFh – 001100h

256 Bytes 0010FFh – 001000h

4KB 00FFFFh – 00F000h 256 Bytes 000FFFh – 000F00h 4KB 00EFFFh – 00E000h 256 Bytes 000EFFh – 000E00h 4KB 00DFFFh – 00D000h 256 Bytes 000DFFh – 000D00h 4KB 00CFFFh – 00C000h 256 Bytes 000CFFh – 000C00h 4KB 00BFFFh – 00B000h 256 Bytes 000BFFh – 000B00h 4KB 00AFFFh – 00A000h 256 Bytes 000AFFh – 000A00h 4KB 009FFFh – 009000h 256 Bytes 0009FFh – 000900h 4KB 008FFFh – 008000h 256 Bytes 0008FFh – 000800h 4KB 007FFFh – 007000h 256 Bytes 0007FFh – 000700h 4KB 006FFFh – 006000h 256 Bytes 0006FFh – 000600h 4KB 005FFFh – 005000h 256 Bytes 0005FFh – 000500h 4KB 004FFFh – 004000h 256 Bytes 0004FFh – 000400h 4KB 003FFFh – 003000h 256 Bytes 0003FFh – 000300h 4KB 002FFFh – 002000h 256 Bytes 0002FFh – 000200h 4KB 001FFFh – 001000h 256 Bytes 0001FFh – 000100h 4KB 000FFFh – 000000h 256 Bytes 0000FFh – 000000h 64KB (Sector 62) 64KB    64KB 32KB 32KB          64KB 64KB (Sector 63) 32KB 32KB 64KB (Sector 0) 32KB 32KB    Internal Sectoring for 64KB 32KB 4KB 1-256 Byte Sector Protection Block Erase Block Erase Block Erase Page Program Function (D8h Command) (52h Command) (20h Command) (02h Command) Block Erase Detail Page Program Detail Page AddressBlock Address RangeRange

3669B–DFLASH–6/09 AT25DF321 5. Device Operation The AT25DF321 is controlled by a set of instructions that are sent from a host controller, com- monly referred to as the SPI Master. The SPI Master communicates with the AT25DF321 via the SPI bus which is comprised of four signal lines: Chip Select (CS ), Serial Clock (SCK), Serial Input (SI), and Serial Output (SO). The SPI protocol defines a total of four modes of operation (mode 0, 1, 2, or 3) with each mode differing in respect to the SCK polarity and phase and how the polarity and phase control the flow of data on the SPI bus. The AT25DF321 supports the two most common modes, SPI Modes 0 and 3. The only difference between SPI Modes 0 and 3 is the polarity of the SCK signal when in the inactive state (when the SPI Master is in standby mode and not transferring any data). With SPI Modes 0 and 3, data is always latched in on the rising edge of SCK and always output on the falling edge of SCK. Figure 5-1. SPI Mode 0 and 3 6. Commands and Addressing A valid instruction or operation must always be started by first asserting the CS pin. After the CS pin has been asserted, the SPI Master must th en clock out a valid 8-bit opcode on the SPI bus. Following the opcode, instruction dependent info rmation such as address and data bytes would then be clocked out by the SPI Master. All opcode, address, and data bytes are transferred with the most significant bit (MSB) first. An operation is ended by deasserting the CS pin. Opcodes not supported by the AT25DF321 will be ignored by the device and no operation will be started. The device will continue to ignore any data presented on the SI pin until the start of the next operation (CS pin being deasserted and then reasserted). In addition, if the CS pin is deas- serted before complete opcode and address information is sent to the device, then no operation will be performed and the device will simply retu rn to the idle state and wait for the next operation. Addressing of the device requires a total of th ree bytes of information to be sent, representing address bits A23-A0. Since the upper address limit of the AT25DF321 memory array is 3FFFFFh, address bits A23-A22 are always ignored by the device. SCK CS SI SO MSB LSB MSB LSB

3669B–DFLASH–6/09 AT25DF321 Table 6-1. Command Listing Command Opcode Address Bytes Dummy Bytes Data Bytes Read Commands Read Array 0Bh 0000 1011 3 1 1+ Read Array (Low Frequency) 03h 0000 0011 3 0 1+ Program and Erase Commands Block Erase (4-KBytes) 20h 0010 0000 3 0 0 Block Erase (32-KBytes) 52h 0101 0010 3 0 0 Block Erase (64-KBytes) D8h 1101 1000 3 0 0 Chip Erase 60h 0110 0000 0 0 0 C7h 1100 0111 0 0 0 Byte/Page Program (1 to 256 Bytes) 02h 0000 0010 3 0 1+ Protection Commands Write Enable 06h 0000 0110 0 0 0 Write Disable 04h 0000 0100 0 0 0 Protect Sector 36h 0011 0110 3 0 0 Unprotect Sector 39h 0011 1001 3 0 0 Global Protect/Unprotect Use Wr ite Status Register command Read Sector Protection Registers 3Ch 0011 1100 3 0 1+ Status Register Commands Read Status Register 05h 0000 0101 0 0 1+ Write Status Register 01h 0000 0001 0 0 1 Miscellaneous Commands Read Manufacturer and Device ID 9Fh 1001 1111 0 0 1 to 4 Deep Power-Down B9h 1011 1001 0 0 0 Resume from Deep Power-Down ABh 1010 1011 0 0 0

3669B–DFLASH–6/09 AT25DF321 7. Read Commands

7.1 Read Array

The Read Array command can be used to sequentia lly read a continuous stream of data from the device by simply providi ng the SCK signal once the initial starting address has been speci- fied. The device incorporates an internal address counter that automatically increments on every clock cycle. Two opcodes, 0Bh and 03h, can be used for the Read Array command. The use of each opcode depends on the maximum SCK frequency that will be used to read data from the device. The 0Bh opcode can be used at any SCK frequency up to the maximum specified by f SCK. The 03h opcode can be used for lower frequency read operations up to the maximum specified by f RDLF. To perform the Read Array operation, the CS pin must first be asserted and the appropriate opcode (0Bh or 03h) must be clocked into the device. After the opcode has been clocked in, the three address bytes must be clocked in to specify the starting address location of the first byte to read within the memory array. If the 0Bh opcode is used, then one don’t care byte must also be clocked in after the three address bytes. After the three address bytes (and the one don’t care byte if using opcode 0Bh) have been clocked in, additional clock cycles will result in se rial data being output on the SO pin. The data is always output with the MSB of a byte first. When the last byte (3FFFFFh) of the memory array has been read, the device will continue reading back at the beginning of the array (000000h). No delays will be incurred when wrapping around from the end of the array to the beginning of the array. Deasserting the CS pin will terminate the read operation and put the SO pin into a high-imped- ance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read. Figure 7-1. Read Array – 0Bh Opcode Figure 7-2. Read Array – 03h Opcode SCK CS SI SO MSB MSB 2310 00001011 67541 0 1 1 981 2 3 9 4 2 4 3 414037 3833 36 353431 3229 30 44 47 48 4645 OPCODE AAAA AAA A A MSB XXXXXXX X MSB MSB DDDDDDD DDD ADDRESS BITS A23-A0 DON'T CARE DATA BYTE 1 HIGH-IMPEDANCE SCK CS SI SO MSB MSB 2310 00000011 67541 0 1 1 981 2 3 7 3 8 33 36 353431 3229 30 39 40 OPCODE AAAA AAA A A MSB MSB DDDDDDD DDD ADDRESS BITS A23-A0 DATA BYTE 1 HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 8. Program and Erase Commands

8.1 Byte/Page Program

The Byte/Page Program command allows anywhere from a single byte of data to 256 bytes of data to be programmed into previously erased memory locations. An erased memory location is one that has all eight bits set to the logical “1” state (a byte value of FFh). Before a Byte/Page Program command can be started, the Write Enable command must have been previously issued to the device (see Write Enable comma nd description) to set the Write Enable Latch (WEL) bit of the Status Register to a logical “1” state. To perform a Byte/Page Program command, an opcode of 02h must be clocked into the device followed by the three address bytes denoting the first byte location of the memory array to begin programming at. After the address bytes have been clocked in, data can then be clocked into the device and will be stored in an internal buffer. If the starting memory address denoted by A23-A0 does not fall on an even 256-byte page boundary (A7-A0 are not all 0), then special ci rcumstances regarding which memory locations will be programmed will apply. In this situation, any data that is sent to the device that goes beyond the end of the page will wrap around back to the beginning of the same page. For exam- ple, if the starting address denoted by A23-A0 is 0000FEh, and three bytes of data are sent to the device, then the first two bytes of data will be prog rammed at addres ses 0000FEh and 0000FFh while the last byte of data will be programmed at address 000000h. The remaining bytes in the page (addresses 000001h through 0000FDh) will be unaffected and will not change. In addition, if more than 256 bytes of data are sent to the device, then only the last 256 bytes sent will be latched into the internal buffer. When the CS pin is deasserted, the device will take the data stored in the internal buffer and pro- gram it into the appropriate memory array loca tions based on the starting address specified by A23-A0 and the number of complete data bytes sent to the device. If less than 256 bytes of data were sent to the device, then the remaining bytes within the page will not be altered. The pro- gramming of the data bytes is internally self-timed and should take place in a time of t PP. The three address bytes and at least one complete byte of data must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on even byte boundaries (multiples of eight bits); otherwise, the device will abort the operation and no data will be pro- grammed into the memory array. In addition, if the address specified by A23-A0 points to a memory location within a sector that is in the protected state (see “Protect Sector” on page 13), then the Byte/Page Program command will not be executed, and the device will return to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will be reset back to the logical “0” state if the program cycle aborts due to an incomplete address being sent, an incomplete byte of data being sent, or be cause the memory location to be programmed is protected. While the device is programming, the Status R egister can be read and will indicate that the device is busy. For faster throughput, it is recommended that the Status Register be polled rather than waiting the t PP time to determine if the data bytes have finished programming. At some point before the program cycle completes, the WEL bit in the Status Register will be reset back to the logical “0” state. The device also incorporates an intelligent prog ramming algorithm that can detect when a byte location fails to program properly. If a programming error arises, it will be indicated by the EPE bit in the Status Register.

3669B–DFLASH–6/09 AT25DF321 Figure 8-1. Byte Program Figure 8-2. Page Program

8.2 Block Erase

A block of 4K-, 32K-, or 64K-bytes can be erased (a ll bits set to the logical “1” state) in a single operation by using one of three different opcodes for the Block Erase command. An opcode of 20h is used for a 4K-byte erase, an opcode of 52h is used for a 32K-byte erase, and an opcode of D8h is used for a 64K-byte erase. Before a Block Erase command can be started, the Write Enable command must have been previously issued to the device to set the WEL bit of the Sta- tus Register to a logical “1” state. To perform a Block Erase, the CS pin must first be asserted and the appropriate opcode (20h, 52h, or D8h) must be clocked into the device. After the opcode has been clocked in, the three address bytes specifying an address within the 4K -, 32K-, or 64K-byte block to be erased must be clocked in. Any additional data clocked into the device will be ignored. When the CS pin is deasserted, the device will erase the appropriate block. The er asing of the block is internally self-timed and should take place in a time of tBLKE. Since the Block Erase command erases a region of bytes, the lower order address bits do not need to be decoded by the device. Therefore, for a 4K-byte erase, address bits A11-A0 will be ignored by the device and their values can be ei ther a logical “1” or “0”. For a 32K-byte erase, address bits A14-A0 will be igno red, and for a 64K-byte erase, address bits A15-A0 will be ignored by the device. Despite the lower order address bits not being decoded by the device, the complete three address bytes must still be clocked into the device before the CS pin is deas- serted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and no erase operation will be performed. SCK CS SI SO MSB MSB 2310 00000010 67541 0 1 1 981 2 3 9 37 3833 36 353431 3229 30 OPCODE HIGH-IMPEDANCE AAAA AAA A A MSB DDDDDDD D ADDRESS BITS A23-A0 DATA IN SCK CS SI SO MSB MSB 2310 00000010 67549 83 9 37 3833 36 353431 3229 30 OPCODE HIGH-IMPEDANCE AA AAA A MSB DDDDDDD D ADDRESS BITS A23-A0 DATA IN BYTE 1 MSB DDDDDDD D DATA IN BYTE n

3669B–DFLASH–6/09 AT25DF321 If the address specified by A23-A0 points to a me mory location within a sector that is in the pro- tected state, then the Block Erase command will not be executed, and the device will return to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will be reset back to the logical “0” state if the erase cycle aborts due to an incomplete address being sent or because a memory location within the region to be erased is protected. While the device is executing a successful erase cycle, the Status Register can be read and will indicate that the device is busy. For faster throughput, it is recommended that the Status Regis- ter be polled rather than waiting the tBLKE time to determine if the device has finished erasing. At some point before the erase cycle completes, the WEL bit in the Status Register will be reset back to the logical “0” state. The device also incorporates an intelligent erasing algorithm that can detect when a byte loca- tion fails to erase properly. If an erase error aris es, it will be indicated by the EPE bit in the Status Register. Figure 8-3. Block Erase

8.3 Chip Erase

The entire memory array can be erased in a single operation by using the Chip Erase command. Before a Chip Erase command can be started, the Write Enable command must have been pre- viously issued to the device to set the WEL bit of the Status Register to a logical “1” state. Two opcodes, 60h and C7h, can be used for the Chip Erase command. There is no difference in device functionality when utilizin g the two opcodes, so they c an be used interchangeably. To perform a Chip Erase, one of the two opcodes (60h or C7h) must be clocked into the device. Since the entire memory array is to be erased, no address bytes need to be clocked into the device, and any data clocked in after the opcode will be ignored. When the CS pin is deasserted, the device will erase the entire memory array. The erasing of the device is internally self-timed and should take place in a time of tCHPE. The complete opcode must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundar y (multiples of eight bits); otherwise, no erase will be performed. In addition, if any sector of the memory array is in the protected state, then the Chip Erase comma nd will not be executed, and the device will return to the idle state once the CS pin has been deasserted. The WEL bit in t he Status Register will be reset back to the logical “0” state if a sector is in the protected state. While the device is executing a successful erase cycle, the Status Register can be read and will indicate that the device is busy. For faster throughput, it is recommended that the Status Regis- SCK CS SI SO MSB MSB 2310 CCCCCCCC 67541 0 1 1 981 2 3 1 29 3027 2826 OPCODE AAAA AAA A A A A A ADDRESS BITS A23-A0 HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 ter be polled rather than waiting the tCHPE time to determine if the device has finished erasing. At some point before the erase cycle completes, the WEL bit in the Status Register will be reset back to the logical “0” state. The device also incorporates an intelligent erasing algorithm that can detect when a byte loca- tion fails to erase properly. If an erase error aris es, it will be indicated by the EPE bit in the Status Register. Figure 8-4. Chip Erase 9. Protection Commands and Features

9.1 Write Enable

The Write Enable command is used to set the Write Enable Latch (WEL) bit in the Status Regis- ter to a logical “1” state. The WEL bit must be set before a program, erase, Protect Sector, Unprotect Sector, or Write Status Register command can be executed. This makes the issuance of these commands a two step process, ther eby reducing the chances of a command being accidentally or erroneously executed. If the WEL bi t in the Status Register is not set prior to the issuance of one of these commands, then the command will not be executed. To issue the Write Enable command, the CS pin must first be asserted and the opcode of 06h must be clocked into the device. No address by tes need to be clocked into the device, and any data clocked in after the opcode will be ignored. When the CS pin is deasserted, the WEL bit in the Status Register will be set to a logical “1 ”. The complete opcode must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasse rted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of the WEL bit will not change. Figure 9-1. Write Enable SCK CS SI SO MSB 2310 CCCCCCCC 6754 OPCODE HIGH-IMPEDANCE SCK CS SI SO MSB 2310 00000110 6754 OPCODE HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321

9.2 Write Disable

The Write Disable command is used to reset the Write Enable Latch (WEL) bit in the Status Reg- ister to the logical “0” state. With the WEL bit reset, all program, erase, Protect Sector, Unprotect Sector, and Write Status Register commands will not be executed. The Write Disable command is also used to exit the Sequential Program Mo de. Other conditions can also cause the WEL bit to be reset; for more details, refer to the WEL bi t section of the Status Register description on page 21. To issue the Write Disable command, the CS pin must first be asserted and the opcode of 04h must be clocked into the device. No address by tes need to be clocked into the device, and any data clocked in after the opcode will be ignored. When the CS pin is deasserted, the WEL bit in the Status Register will be reset to a logical “0”. The complete opcode must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasse rted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of the WEL bit will not change. Figure 9-2. Write Disable

9.3 Protect Sector

Every physical sector of the devi ce has a corresponding single-bit Sector Protection Register that is used to control the so ftware protection of a sector. Up on device power-up or after a device reset, each Sector Protection Register will default to the logical “1” state indicating that all sectors are protected and cannot be programmed or erased. Issuing the Protect Sector co mmand to a particular sector add ress will set the corresponding Sector Protection Register to the logical “1” state. The following table out lines the two states of the Sector Protection Registers. Before the Protect Sector command can be issued, the Write Enable command must have been previously issued to set the WEL bi t in the Status Register to a lo gical “1”. To issue the Protect Sector command, the CS pin must first be asserted and the opcode of 36h must be clocked into the device followed by three address bytes designating any address within the sector to be locked. Any additional data clocked into the device will be ignored. When the CS pin is deas- serted, the Sector Protection Register corresponding to the physical sector addressed by A23- SCK CS SI SO MSB 2310 00000100 6754 OPCODE HIGH-IMPEDANCE Table 9-1. Sector Protection Register Values Value Sector Protection Status 0 Sector is unprotected and ca n be programmed and erased. 1 Sector is protected and cannot be programm ed or erased. This is the default state.

3669B–DFLASH–6/09 AT25DF321 A0 will be set to the logical “1” state, and the sector itself will then be protected from program and erase operations. In addition, the WEL bit in the Status Register will be reset back to the log- ical “0” state. The complete three address bytes must be clocked into the device before the CS pin is deas- serted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will ab ort the operation, the state of t he Sector Protection Register will be unchanged, and the WEL bit in the Status Register will be reset to a logical “0”. As a safeguard against accidental or erroneous protecting or unprotecting of sectors, the Sector Protection Registers can themselves be locked from updates by using the SPRL (Sector Protec- tion Registers Locked) bit of the St atus Register (please refer to “Status Register Commands” on page 20 for more details). If the Sector Protection Registers are locked, then any attempts to issue the Protect Sector command will be ignored, and the device will reset the WEL bit in the Status Register back to a logical “0” and return to the idle state once the CS pin has been deasserted. Figure 9-3. Protect Sector

9.4 Unprotect Sector

Issuing the Unprotect Sector co mmand to a particular sector ad dress will reset the correspond- ing Sector Protection Register to the logical “0” state (see Table 9-1 on page 13 for Sector Protection Register values). Every physical sector of the device has a corresponding single-bit Sector Protection Register that is used to control the software protection of a sector. Before the Unprotect Sector command can be issued, the Write Enable command must have been previously issued to set the WEL bit in the Status Register to a logical “1”. To issue the Unprotect Sector command, the CS pin must first be asserted and the opcode of 39h must be clocked into the device. After the opcode has been clocked in, the three address bytes designat- ing any address within the sector to be unlocked must be clocked in. Any additional data clocked into the device after the address bytes will be ignored. When the CS pin is deasserted, the Sec- tor Protection Register corresponding to the sector addressed by A23-A0 will be reset to the logical “0” state, and the sector itself will be unprotected. In addition, the WEL bit in the Status Register will be reset back to the logical “0” state. The complete three address bytes must be clocked into the device before the CS pin is deas- serted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will ab ort the operation, the state of t he Sector Protection Register will be unchanged, and the WEL bit in the Status Register will be reset to a logical “0”. SCK CS SI SO MSB MSB 2310 00110110 67541 0 1 1 981 2 3 1 29 3027 2826 OPCODE AAAA AAA A A A A A ADDRESS BITS A23-A0 HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 As a safeguard against accidental or erroneous locking or unlocking of sectors, the Sector Pro- tection Registers can themselves be locked from updates by using the SPRL (Sector Protection Registers Locked) bit of the Status Register (please refer to “Status Register Commands” on page 20 for more details). If the Sector Protection Registers are locked, then any attempts to issue the Unprotect Sector command will be ignored, and the device will reset the WEL bit in the Status Register back to a logical “0” and return to the idle state once the CS pin has been deasserted. Figure 9-4. Unprotect Sector

9.5 Global Protect/Unprotect

The Global Protect and Global Unprotect features can work in conjunction with the Protect Sec- tor and Unprotect Sector functions. For exampl e, a system can globally protect the entire memory array and then use the Unprotect Sector command to individually unprotect certain sec- tors and individually reprotect t hem later by using the Protec t Sector command. Likewise, a system can globally unprotect the entire memory array and then individually protect certain sec- tors as needed. Performing a Global Protect or Global Unprotec t is accomplished by writing a certain combina- tion of data to the Status Regist er using the Write Status Regi ster command (see “Write Status Register” section on page 22 for command execution details). The Write Status Register com- mand is also used to modify the SPRL (Sector Protection Registers Lo cked) bit to control hardware and software locking. To perform a Global Protect, the appropriate WP pin and SPRL conditions must be met and the system must write a logical “1” to bits 5, 4, 3, and 2 of the Status Register. Conversely, to per- form a Global Unprotect, the same WP and SPRL conditions must be met but the system must write a logical “0” to bits 5, 4, 3, and 2 of the Status Register. Table 9-2 details the conditions necessary for a Global Protect or Global Unprotect to be performed. SCK CS SI SO MSB MSB 2310 00111001 67541 0 1 1 981 2 3 1 29 3027 2826 OPCODE AAAA AAA A A A A A ADDRESS BITS A23-A0 HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 Essentially, if the SPRL bit of the Status Register is in the logical “0” state (Sector Protection Registers are not locked), then writing a 00h to the Status Register will perform a Global Unpro- tect without changing the state of the SPRL bit. Similarly, writing a 7Fh to the Status Register will perform a Global Protect and keep the SPRL bit in the logical “0” state. The SPRL bit can, of course, be changed to a logical “1” by writing an FFh if software-locking or hardware-locking is desired along with the Global Protect. Table 9-2. Valid SPRL and Global Protect/Unprotect Conditions WP State Current SPRL Value New Write Status Register Data Protection Operation New SPRL Value Bit 7 6 5 4 3 2 1 0 0 x 0 0 0 0 x x 0 x 0 0 0 1 x x 0 x 1 1 1 0 x x 0 x 1 1 1 1 x x 1 x 0 0 0 0 x x 1 x 0 0 0 1 x x 1 x 1 1 1 0 x x 1 x 1 1 1 1 x x Global Unprotect – all Sector Protection Registers reset to 0 No change to current protection. No change to current protection. No change to current protection. Global Protect – all Sector Protection Registers set to 1 Global Unprotect – all Sector Protection Registers reset to 0 No change to current protection. No change to current protection. No change to current protection. Global Protect – all Sector Protection Registers set to 1 0 1 x x x x x x x x No change to the current protection level. All sectors currently protected will remain protected and all sectors currently unprotected will remain unprotected. The Sector Protection Registers are hard-locked and cannot be changed when the WP pin is LOW and the current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur. In addition, the SPRL bit cannot be changed (the WP pin must be HIGH in order to change SPRL back to a 0). 0 x 0 0 0 0 x x 0 x 0 0 0 1 x x 0 x 1 1 1 0 x x 0 x 1 1 1 1 x x 1 x 0 0 0 0 x x 1 x 0 0 0 1 x x 1 x 1 1 1 0 x x 1 x 1 1 1 1 x x Global Unprotect – all Sector Protection Registers reset to 0 No change to current protection. No change to current protection. No change to current protection. Global Protect – all Sector Protection Registers set to 1 Global Unprotect – all Sector Protection Registers reset to 0 No change to current protection. No change to current protection. No change to current protection. Global Protect – all Sector Protection Registers set to 1 0 x 0 0 0 0 x x 0 x 0 0 0 1 x x 0 x 1 1 1 0 x x 0 x 1 1 1 1 x x 1 x 0 0 0 0 x x 1 x 0 0 0 1 x x 1 x 1 1 1 0 x x 1 x 1 1 1 1 x x No change to the current protection level. All sectors currently protected will remain protected, and all sectors currently unprotected will remain unprotected. The Sector Protection Registers are soft-locked and cannot be changed when the current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur. However, the SPRL bit can be changed back to a 0 from a 1 since the WP pin is HIGH. To perform a Global Protect/Unprotect, the Write Status Register command must be issued again after the SPRL bit has been changed from a 1 to a 0.

3669B–DFLASH–6/09 AT25DF321 If the desire is to only change the SPRL bit without performing a Global Protect or Global Unpro- tect, then the system can simply write a 0Fh to the Status Register to change the SPRL bit from a logical “1” to a logical “0” provided the WP pin is deasserted. Likewise, the system can write an F0h to change the SPRL bit from a logical “0” to a logical “1” without affecting the current sector protection status (no changes will be made to the Sector Protection Registers). When writing to the Status Register, bits 5, 4, 3, and 2 will not actually be modified but will be decoded by the device for the pur poses of the Global Protect and Global Unprotect functions. Only bit 7, the SPRL bit, will actually be modified. Therefore, when reading the Status Register, bits 5, 4, 3, and 2 will not reflect the values wri tten to them but will instead indicate the status of the WP pin and the sector protection status. Please refer to the “Read Status Register” section and Table 10-1 on page 20 for details on the Status Register format and what values can be read for bits 5, 4, 3, and 2.

9.6 Read Sector Pr otection Registers

The Sector Protection Registers can be read to determine the current software protection status of each sector. Reading the Se ctor Protection Registers, however, will not determine the status of the WP pin. To read the Sector Protection Regist er for a particular sector, the CS pin must first be asserted and the opcode of 3Ch must be clocked in. Once the opcode has been clocked in, three address bytes designating any address withi n the sector must be clocked in. After the last address byte has been clocked in, the device will begin output ting data on the SO pin during every subse- quent clock cycle. The data being output will be a repeating byte of either FFh or 00h to denote the value of the appropriate Sector Protection Register Deasserting the CS pin will terminate the read operation and put the SO pin into a high-imped- ance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read. In addition to reading the individual Sector Pr otection Registers, the Software Protection Status (SWP) bit in the Status Register can be read to determine if all, some, or none of the sectors are software protected (please refer to “Status Register Commands” on page 20 for more details). Table 9-3. Read Sector Protection Register – Output Data Output Data Sector Protection Register Value 00h Sector Protection Register valu e is 0 (sector is unprotected). FFh Sector Protection Register value is 1 (sector is protected).

3669B–DFLASH–6/09 AT25DF321 Figure 9-5. Read Sector Protection Register

9.7 Protected States and the Write Protect (WP) Pin

The WP pin is not linked to the memory array itself and has no direct effect on the protection sta- tus of the memory array. Instead, the WP pin, in conjunction with the SPRL (Sector Protection Registers Locked) bit in the Status Register, is used to control the hardware locking mechanism of the device. For hardware locking to be active, two conditions must be met – the WP pin must be asserted and the SPRL bit must be in the logical “1” state. When hardware locking is active, the Sector Protection Registers are locked and the SPRL bit itself is also locked. Therefore, sectors that are protected will be locked in the protected state, and sectors that are unprotected will be locked in the unprotected state. These states cannot be changed as long as hardware locking is active, so the Protect Sector, Unprotect Sector, and Write Status Register commands will be ignored. In order to modi fy the protection status of a sector, the WP pin must first be deasserted, and the SPRL bit in the Status Register must be reset back to the logical “0” state using the Write Status Register command. When resetting the SPRL bit back to a logical “0”, it is not possible to perform a Global Protect or Global Unprotect at the same time since the Sect or Protection Registers remain soft-locked until after the Write Status Register command has been executed. If the WP pin is permanently connected to GND, then once the SPRL bit is set to a logical “1”, the only way to reset the bit back to the logical “0” state is to power-cycle or reset the device. This allows a system to power-up with all sect ors software protected but not hardware locked. Therefore, sectors can be unprotected and protec ted as needed and then hardware locked at a later time by simply setting the SPRL bit in the Status Register. When the WP pin is deasserted, or if the WP pin is permanently connected to VCC, the SPRL bit in the Status Register can still be set to a logical “1” to lock the Sector Protection Registers. This provides a software locking ability to prevent erroneous Protect Sector or Unprotect Sector com- mands from being processed. When changing the SPRL bit to a logical “1” from a logical “0”, it is also possible to perform a Global Protect or Global Unprotect at the same time by writing the appropriate values into bits 5, 4, 3, and 2 of the Status Register. SCK CS SI SO MSB MSB 2310 00111100 67541 0 1 1 981 2 3 7 3 8 33 36 353431 3229 30 39 40 OPCODE AAAA AAA A A MSB MSB DDDDDDD DDD ADDRESS BITS A23-A0 DATA BYTE HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 The tables below detail the various protection and locking states of the device. Note: 1. “n” represents a sector number Table 9-4. Software Protection Register States WP Sector Protection Register n(1) Sector n(1) X (Don't Care)

0 Unprotected

Table 9-5. Hardware and Software Locking WP SPRL Locking SPRL Change Allowed Sector Protection Registers 0 0 Can be modified from 0 to 1 Unlocked and modifiable using the Protect and Unprotect Sector commands. Global Protect and Unprotect can also be performed.

01 Hardware

Locked in current state. Protect and Unprotect Sector commands will be ignored. Global Protect and Unprotect cannot be performed. 1 0 Can be modified from 0 to 1 Unlocked and modifiable using the Protect and Unprotect Sector commands. Global Protect and Unprotect can also be performed.

11 Software

Locked Can be modified from 1 to 0 Locked in current state. Protect and Unprotect Sector commands will be ignored. Global Protect and Unprotect cannot be performed.

3669B–DFLASH–6/09 AT25DF321 10. Status Register Commands

10.1 Read Status Register

The Status Register can be read to determine the device’s ready/busy status, as well as the sta- tus of many other functions such as Hardware Locking and Software Protection. The Status Register can be read at any ti me, including during an internally self-timed program or erase operation. To read the Status Register, the CS pin must first be asserted and the opcode of 05h must be clocked into the device. After the last bit of the opcode has been clocked in, the device will begin outputting Status Register data on the SO pin during every subsequent clock cycle. After the last bit (bit 0) of the Status Regi ster has been clocked out, the se quence will repeat itself starting again with bit 7 as long as the CS pin remains asserted and the SCK pin is being pulsed. The data in the Status Register is constantly being updated, so each repeating sequence will output new data. Deasserting the CS pin will terminate the Read Status Register operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read. Notes: 1. Only bit 7 of the Status Register will be mo dified when using the Write Status Register command. 2. R/W = Readable and writeable R = Readable only Table 10-1. Status Register Format Bit(1) Name Type (2) Description

7 SPRL Sector Protection Registers Locked R/W

0 Sector Protection Regist ers are unlocked (default). 1 Sector Protection Registers are locked. 6 RES Reserved for future use R 0 Reserved for future use.

5 EPE Erase/Program Error R

0 Erase or program operation was successful. 1 Erase or program error detected.

4 WPP Write Protect (WP ) Pin Status R

0W P is asserted. 1W P is deasserted. 3:2 SWP Software Protection Status R

00 All sectors are software unprotected (all Sector

Protection Registers are 0). Some sectors are software protected. Read individual Sector Protection Registers to determine which sectors are protected. 10 Reserved for future use.

11 All sectors are software protected (all Sector

Protection Registers are 1 – default).

1 WEL Write Enable Latch Status R

0 Device is not write enabled (default). 1 Device is write enabled.

0 RDY/BS

0 Device is ready. 1 Device is busy with an internal operation.

3669B–DFLASH–6/09 AT25DF321

10.1.1 SPRL Bit

The SPRL bit is used to control whether the Sect or Protection Registers can be modified or not. When the SPRL bit is in the logical “1” state, all Sector Protection Registers are locked and can- not be modified with the Protect Sector and Un protect Sector commands (the device will ignore these commands). In addition, the Global Protect and Global U nprotect features cannot be per- formed. Any sectors that are presently protected will remain protected, and any sectors that are presently unprotected will remain unprotected. When the SPRL bit is in the logi cal “0” state, all Sector Protection Registers are unlocked and can be modified (the Protect Sector and Unprotect Sector commands, as well as the Global Pro- tect and Global Unprotect features, will be processed as normal). The SPRL bit defaults to the logical “0” state after a power-up or a device reset. The SPRL bit can be modified freely whenever the WP pin is deasserted. However, if the WP pin is asserted, then the SPRL bit may only be changed from a logical “0” (Sector Protection Regis- ters are unlocked) to a logical “1” (Sector Protection Registers are locked). In order to reset the SPRL bit back to a logical “0” using the Write Status Register command, the WP pin will have to first be deasserted. The SPRL bit is the only bit of the Status Register that can be user modified via the Write Status Register command.

10.1.2 WPP Bit

The WPP bit can be read to determine if the WP pin has been asserted or not.

10.1.3 EPE Bit

The EPE bit indicates whether the last erase or program operation completed successfully or not. If at least one byte during the erase or program operation did not erase or program properly, then the EPE bit will be set to the logical “1” state. The EPE bit will not be set if an erase or pro- gram operation aborts for any reason such as an attempt to erase or program a protected region or if the WEL bit is not set prior to an erase or program operation. The EPE bit will be updated after every erase and program operation.

10.1.4 SWP Bits

The SWP bits provide feedback on the software protection status for the device. There are three possible combinations of the SWP bits that indicate whether none, some, or all of the sectors have been protected using the Protect Sector co mmand or the Global Protect feature. If the SWP bits indicate that some of the sectors ha ve been protected, then the individual Sector Pro- tection Registers can be read with the Read Sector Protection Registers command to determine which sectors are in fact protected.

10.1.5 WEL Bit

The WEL bit indicates the current status of the internal Write Enable Latch. When the WEL bit is in the logical “0” state, the device will not accept any program, erase, Pr otect Sector, Unprotect Sector, or Write Status Register commands. The WEL bit defaults to the logical “0” state after a device power-up or reset. In addi tion, the WEL bit will be reset to the logical “0” state automati- cally under the following conditions:

3669B–DFLASH–6/09 AT25DF321

• Write Disable operation completes successfully
• Write Status Register operation completes successfully or aborts
• Protect Sector operation completes successfully or aborts
• Unprotect Sector operation completes successfully or aborts
• Byte/Page Program operation completes successfully or aborts
• Block Erase operation completes successfully or aborts
• Chip Erase operation completes successfully or aborts If the WEL bit is in the logical “1” state, it will not be reset to a logical “0” if an operation aborts due to an incomplete or unrecognized opcode being clocked into the device before the CS pin is deasserted. In order for the WEL bit to be reset when an operation aborts prematurely, the entire opcode for a program, erase, Protect Sector, Unpr otect Sector, or Write Status Register com- mand must have been clocked into the device.

10.1.6 RDY/BSY Bit

The RDY/BSY bit is used to determi ne whether or not an internal operation, such as a program or erase, is in progress. To poll the RDY/BSY bit to detect the completion of a program or erase cycle, new Status Register data must be contin ually clocked out of the device until the state of the RDY/BSY bit changes from a logical “1” to a logical “0”. Figure 10-1. Read Status Register

10.2 Write Status Register

The Write Status Register command is used to modify the SPRL bit of the Status Register and/or to perform a Global Protect or Global Unprotect operation. Before the Write Status Regis- ter command can be issued, the Write Enable co mmand must have been previously issued to set the WEL bit in the Status Register to a logical “1”. To issue the Write Status Register command, the CS pin must first be asserted and the opcode of 01h must be clocked into th e device followed by one byte of data. The one byte of data con- sists of the SPRL bit value, a don't care bit, f our data bits to denote whether a Global Protect or Unprotect should be performed, and tw o additional don’t care bits (see Table 10-2). Any addi- tional data bytes that are sent to the device will be ignored. When the CS pin is deasserted, the SPRL bit in the Status Register will be modified and the WEL bit in the Status Register will be reset back to a logical “0”. The values of bits 5, 4, 3, and 2 and the state of the SPRL bit before the Write Status Register command was executed (the prior state of the SPRL bit) will determine whether or not a Global Protect or Global Unprotect will be perfomed. Please refer to the “Global Protect/Unprotect” section on page 15 for more details. SCK CS SI SO MSB 2310 00000101 67541 0 1 1 981 2 2 1 2 2 17 20 191815 1613 14 23 24 OPCODE MSB MSB DDDDDD D DDD MSB DDDDD DDD STATUS REGISTER DATA STATUS REGISTER DATA HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 The complete one byte of data must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); other- wise, the device will abort the oper ation, the state of the SPRL bi t will not change, no potential Global Protect or Unprotect will be performed, and the WEL bit in the Status Register will be reset back to the logical “0” state. If the WP pin is asserted, then the SPRL bit can only be set to a logical “1”. If an attempt is made to reset the SPRL bit to a logical “0” while the WP pin is asserted, then the Write Status Register command will be ignored, and the WEL bit in the Status Register will be reset back to the logical “0” state. In order to reset the SPRL bit to a logical “0”, the WP pin must be deasserted. Figure 10-2. Write Status Register 11. Other Commands and Functions

11.1 Read Manufacturer and Device ID

Identification information can be read from the dev ice to enable systems to electronically query and identify the device while it is in system. The identification method and the command opcode comply with the JEDEC standard for “Manufacturer and Device ID Read Methodology for SPI Compatible Serial Interface Memory Devices”. The type of information that can be read from the device includes the JEDEC defined Manufacturer ID, the vendor specific Device ID, and the ven- dor specific Extended Device Information. To read the identification information, the CS pin must first be asserted and the opcode of 9Fh must be clocked into the device. After the opcode has been clocked in, the device will begin out- putting the identification data on the SO pin during the subsequent cloc k cycles. The first byte that will be output will be the Manufacturer ID followed by two bytes of Device ID information. The fourth byte output will be the Extended Device Information String Length, which will be 00h indicating that no Extended Device Information fo llows. After the Extend ed Device Information String Length byte is output, the SO pin will go into a high-impedance state; therefore, additional clock cycles will have no affect on the SO pi n and no data will be output. As indicated in the JEDEC standard, reading the Extended Device Information String Length and any subsequent data is optional. Table 10-2. Write Status Register Format Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SPRL X Global Protect/Unprotect X X SCK CS SI SO MSB 2310 0000000 67541 0 1 1 981 4 1 5 1312 OPCODE MSB 1DXDDDDX X STATUS REGISTER IN HIGH-IMPEDANCE

3669B–DFLASH–6/09 AT25DF321 Deasserting the CS pin will terminate the Manufacturer and Device ID read operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read. Figure 11-1. Read Manufacturer and Device ID Table 11-1. Manufacturer and Device ID Information Byte No. Data Type Value

1 Manufacturer ID 1Fh

2 Device ID (Part 1) 47h

3 Device ID (Part 2) 00h

4 Extended Device Information String Length 00h

Table 11-2. Manufacturer and Device ID Details Data Type Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Hex Value Details Manufacturer ID JEDEC Assigned Code 1Fh JEDEC Code: 0001 1111 (1Fh for Atmel) 00011111 Device ID (Part 1) Family Code Density Code 47h Family Code: Density Code: 010 (AT25/26DFxxx series) 00111 (32-Mbit)01000111 Device ID (Part 2) Sub Code Product Version Code 00h Sub Code: Product Version: 000 (Standard series) 00000 (Initial version)00000000 SCK CS SI SO 9Fh 87 38 OPCODE 1Fh 47h 00h 00h MANUFACTURER ID DEVICE ID BYTE 1 DEVICE ID BYTE 2 EXTENDED DEVICE INFORMATION STRING LENGTH HIGH-IMPEDANCE 14 1615 22 2423 30 3231 Note: Each transition shown for SI and SO represents one byte (8 bits)

3669B–DFLASH–6/09 AT25DF321

11.2 Deep Power-Down

During normal operation, the device will be placed in the standby mode to consume less power as long as the CS pin remains deasserted and no internal operation is in progress. The Deep Power-Down command offers the ability to place the device into an even lower power consump- tion state called the Deep Power-Down mode. When the device is in the Deep Power-Down mode, all commands including the Read Status Register command will be ignored with the e xception of the Resume from Deep Power-Down command. Since all commands will be ignored, the mode can be used as an extra protection mechanism against program and erase operations. Entering the Deep Power-Down mode is accomplished by simply asserting the CS pin, clocking in the opcode of B9h, and then deasserting the CS pin. Any additional data clocked into the device after the opcode will be ignored. When the CS pin is deasserted, the device will enter the Deep Power-Down mode within the maximum time of tEDPD. The complete opcode must be clocked in before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and return to the standby mode once the CS pin is deasserted. In addition, the device will default to the standby mode after a power-cycle or a device reset. The Deep Power-Down command will be ignored if an internally self-timed operation such as a program or erase cycle is in progress. The Deep Power-Down command must be reissued after the internally self-timed operation has been comp leted in order for the device to enter the Deep Power-Down mode. Figure 11-2. Deep Power-Down SCK CS SI SO MSB ICC 2310 10111001 6754 OPCODE HIGH-IMPEDANCE Standby Mode Current Active Current Deep Power-Down Mode Current tEDPD

3669B–DFLASH–6/09 AT25DF321

11.3 Resume from Deep Power-Down

In order exit the Deep Power-Down mode and re sume normal device operation, the Resume from Deep Power-Down command must be issu ed. The Resume from Deep Power-Down com- mand is the only command that the device will recognize while in the Deep Power-Down mode. To resume from the Deep Power-Down mode, the CS pin must first be asserted and opcode of ABh must be clocked into the device. Any addi tional data clocked into the device after the opcode will be ignored. When the CS pin is deasserted, the devic e will exit the Deep Power- Down mode within the maximum time of t RDPD and return to the standby mode. After the device has returned to the standby mode, normal command operations such as Read Array can be resumed. If the complete opcode is not clocked in before the CS pin is deasserted, or if the CS pin is not deasserted on an even byte bo undary (multiples of eight bits), then the device will abort the operation and return to the Deep Power-Down mode. Figure 11-3. Resume from Deep Power-Down SCK CS SI SO MSB ICC 2310 10101011 6754 OPCODE HIGH-IMPEDANCE Deep Power-Down Mode Current Active Current Standby Mode Current tRDPD

3669B–DFLASH–6/09 AT25DF321

11.4 Hold

The HOLD pin is used to pause the serial communica tion with the device without having to stop or reset the clock sequence. The Hold mode, however, does not have an affect on any internally self-timed operations such as a program or erase cycle. Therefore, if an erase cycle is in prog- ress, asserting the HOLD pin will not pause the operation, and the erase cycle will continue until it is finished. The Hold mode can only be entered while the CS pin is asserted. The Hold mode is activated simply by asserting the HOLD pin during the SCK low pulse. If the HOLD pin is asserted during the SCK high pulse, then the Hold mode won't be started until the beginning of the next SCK low pulse. The device will remain in the Hold mode as long as the HOLD pin and CS pin are asserted. While in the Hold mode, the SO pin will be in a high-impedance state. In addition, both the SI pin and the SCK pin will be ignored. The WP pin, however, can still be asserted or deasserted while in the Hold mode. To end the Hold mode and resume serial communication, the HOLD pin must be deasserted during the SCK low pulse. If the HOLD pin is deasserted during the SCK high pulse, then the Hold mode won't end until the beginning of the next SCK low pulse. If the CS pin is deasserted while the HOLD pin is still asserted, then any operation that may have been star ted will be aborted, and the device will reset the WEL bit in the Status Register back to the logical “0” state. Figure 11-4. Hold Mode SCK CS HOLD Hold HoldHold

3669B–DFLASH–6/09 AT25DF321 12. Electrical Specifications

12.1 Absolute Maximum Ratings*

Maximum Ratings” may cause permanent dam- age to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. All Input Voltages (including NC Pins) All Output Voltages CC + 0.5V

12.2 DC and AC Operating Range

Operating Temperature (Case) Ind. -40 °C to +85°C VCC Power Supply 2.7V to 3.6V

12.3 DC Characteristics

Symbol Parameter Condition Min Typ Max Units ISB Standby Current CS, WP, HOLD = VCC, all inputs at CMOS levels 25 35 µA IDPD Deep Power-Down Current CS, WP, HOLD = VCC, all inputs at CMOS levels 15 25 µA ICC1 Active Current, Read Operation f = 70 MHz, IOUT = 0 mA, CS = VIL, VCC = Max 11 16 mA f = 66 MHz, IOUT = 0 mA, CS = VIL, VCC = Max 10 15 f = 50 MHz; IOUT = 0 mA, CS = VIL, VCC = Max 91 4 f = 33 MHz, IOUT = 0 mA, CS = VIL, VCC = Max 81 2 f = 20 MHz, IOUT = 0 mA, CS = VIL, VCC = Max 71 0 ICC2 Active Current, Program Operation CS = VCC, VCC = Max 12 18 mA ICC3 Active Current, Erase Operation CS = VCC, VCC = Max 14 20 mA ILI Input Leakage Current V IN = CMOS levels 1 µA ILO Output Leakage Current V OUT = CMOS levels 1 µA VIL Input Low Voltage 0.3 x VCC V VIH Input High Voltage 0.7 x V CC V VOL Output Low Voltage I OL = 1.6 mA, VCC = Min 0.4 V VOH Output High Voltage I OH = -100 µA V CC - 0.2 V

3669B–DFLASH–6/09 AT25DF321 Notes: 1. Not 100% tested (value guaranteed by design and characterization). 2. 15 pF load at 70 MHz, 30 pF load at 66 MHz. 3. Only applicable as a constraint for the Write Status Register command when SPRL = 1.

12.4 AC Characteristics

Symbol Parameter Min Max Units fSCK Serial Clock (SCK) Frequency 70 MHz fRDLF SCK Frequency for Read Array (Low Frequency – 03h opcode) 33 MHz tSCKH SCK High Time 6.8 ns tSCKL SCK Low Time 6.8 ns tSCKR (1) SCK Rise Time, Peak-to-Peak (Slew Rate) 0.1 V/ns tSCKF (1) SCK Fall Time, Peak-to-Peak (Slew Rate) 0.1 V/ns tCSH Chip Select High Time 50 ns tCSLS Chip Select Low Setup Time (relative to SCK) 5 ns tCSLH Chip Select Low Hold Time (relative to SCK) 5 ns tCSHS Chip Select High Setup Time (relative to SCK) 5 ns tCSHH Chip Select High Hold Time (relative to SCK) 5 ns tDS Data In Setup Time 2 ns tDH Data In Hold Time 3 ns tDIS (1) Output Disable Time 6n s tV (2) Output Valid Time 6n s tOH Output Hold Time 0 ns tHLS HOLD Low Setup Time (relative to SCK) 5 ns tHLH HOLD Low Hold Time (relative to SCK) 5 ns tHH HOLD High Setup Time (relative to SCK) 5 ns tHHH HOLD High Hold Time (relative to SCK) 5 ns tHLQZ (1) HOLD Low to Output High-Z 6 ns tHHQX (1) HOLD High to Output Low-Z 6 tWPS (1)(3) Write Protect Setup Time 20 ns tWPH (1)(3) Write Protect Hold Time 100 ns tSECP (1) Sector Protect Time (from Chip Select High) 20 ns tSECUP (1) Sector Unprotect Time (from Chip Select High) 20 ns tEDPD (1) Chip Select High to Deep Power-Down 3 µs tRDPD (1) Chip Select High to Standby Mode 3 µs

3669B–DFLASH–6/09 AT25DF321 Notes: 1. Not 100% tested (value guaranteed by design and characterization).

12.7 Input Test Waveforms and Measurement Levels

12.8 Output Test Load

12.5 Program and Er ase Characteristics

Symbol Parameter Min Typ Max Units tPP Page Program Time (256 Bytes) 1.5 5.0 ms tBP Byte Program Time 6 µs tBLKE Block Erase Time 4-Kbyte 50 200 ms32-Kbyte 350 600 64-Kbyte 600 950 tCHPE (1) Chip Erase Time 36 56 sec tWRSR (1) Write Status Register Time 200 ns

12.6 Power-Up Conditions

Symbol Parameter Min Max Units tVCSL Minimum VCC to Chip Select Low Time 50 µs tPUW Power-up Device Delay Before Program or Erase Allowed 10 ms VPOR Power-On Reset Voltage 1.5 2.5 V AC DRIVING LEVELS AC MEASUREMENT LEVEL0.45V 1.5V 2.4V tR, tF < 2 ns (10% to 90%) DEVICE UNDER TEST 30 pF

3669B–DFLASH–6/09 AT25DF321 14. Ordering Information

14.1 Green Package Options (Pb/ Halide-free/RoHS Compliant)

fSCK (MHz) Ordering Code Package Operation Range

70 AT25DF321-SU 8S2 Industrial

(-40°C to +85°C)70 AT25DF321-S3U 16S Package Type 8S2 8-lead, 0.209" Wide, Plastic Gull Wing Small Outline Package (EIAJ SOIC) 16S 16-lead, 0.300" Wide, Plastic Gull Wing Small Outline Package (SOIC)

3669B–DFLASH–6/09 AT25DF321 15. Packaging Information 15.1 8S2 – EIAJ SOIC TITLE DRAWING NO. GPC REV. Package Drawing Contact: packagedrawings@atmel.com 8S2STN F 8S2, 8-lead, 0.208” Body, Plastic Small Outline Package (EIAJ) 4/15/08 COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information. 2. Mismatch of the upper and lower dies and resin burrs aren't included. 3. Determines the true geometric position. A 1.70 2.16 A1 0.05 0.25 b 0.35 0.48 4 C 0.15 0.35 4 D 5.13 5.35 E1 5.18 5.40 2 E 7.70 8.26 L 0.51 0.85 θ 0° 8° e 1.27 BSC 3 θθ NN EE TOP VIEWTOP VIEW CC E1E1 END VIEWEND VIEW AA bb LL A1A1 ee DD SIDE VIEWSIDE VIEW

3669B–DFLASH–6/09 AT25DF321 15.2 16S – SOIC

2325 Orchard Parkway

San Jose, CA 95131 TITLE DRAWING NO. R REV. 16S, 16-lead, 0.300" Wide Body, Plastic Gull Wing Small Outline Package (SOIC) 11/02/05 16S A E L Side View Top View End ViewHE b N e A D C COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MS-013, Variation AA for additional information. 2. Dimension D does not include mold Flash, protrusions or gate burrs. Mold Flash, protrusion and gate burrs shall not exceed 0.15 mm (0.006") per side. 3. Dimension E does not include inter-lead Flash or protrusion. Inter-lead flash and protrusions shall not exceed 0.25 mm (0.010") per side. 4. L is the length of the terminal for soldering to a substrate. A 2.35 – 2.65 A1 0.10 – 0.30 b 0.31 – 0.51 D 10.30 BSC 2 E 7.50 BSC 3 H 10.30 BSC L 0.40 – 1.27 4 e 1.27 BSC C 0.20 0.33

3669B–DFLASH–6/09 AT25DF321 16. Revision History Revision Level – Release Date History A – July 2007 Initial release B – June 2009 Corrected errors in datasheet. - Changed Deep Power-Down Current typical value from 4 µa to 15 µa - Changed Deep Power-Down Current maximum value from 8 µa to 25 µa

3669B–DFLASH–6/09 Headquarters International Atmel Corporation San Jose, CA 95131 USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Asia Room 1219 Chinachem Golden Plaza

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