MA28139

MA28139 DYNEX | Alldatasheet

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The OBT ASIC will interface any user to the ESA On Board Data Handling bus. Developed under ESA Contract, it conforms to ESA OBDH, Digital Bus Interface and Internal User Bus Standards. The OBT has 2 separate functions. The first is a 5 channel modem which, on the bus side, provides the digital waveforms necessary to operate the Litton Bus drivers, and receives the outputs of the Litton bus detectors. On the user side, it provides an input / output at Digital Bus Interface level. The second function, internally coupled to the first, provides a multiplexing / demultiplexing function of the DBI signals down to Internal User Bus levels and vectored 16 bit serial register read and write commands (see section 7.2 of ESA standard TTC-B-01). In effect, the second function of the OBT provides the core of an RTU. The Interrogation and Response bus data streams of the two functions may be either coupled together (in RT mode) or isolated (in CT mode). The device may hence be used as a modem only, an RTU kernel only or as a combined modem and RTU kernel. In RT mode, the Interrogation bus data stream can be observed and the Response bus data from associated devices, such as an MA28138 Remote Bus Interface, can be combined with that from the RTU kernel before being used by the modem circuits to modulate the Response bus. Bi-directional access to the Block Transfer bus is provided in either mode. When used to interface a central terminal to the OBDH bus, the OBT should be continuously clocked in order to output timing to all users on the I-bus as dummy interrogations from the CT. Commands and telemetry are normally sent on the I and BT busses whilst responses and telemetry normally return on the R and BT busses. Figure 1: Block Diagram CONTROL LOGIC RTU KERNEL CONTROL PINS CLK DETECTOR, WATCHDOG DIGITAL BUS INTERFACE INTERNAL USER BUS CONFIGURATION PINS OBDH BUS I R BT I Rx R Rx I (CTU) R (RTU) BT Rx BT Rx Tx

FEATURES

n Single CMOS-SOS ASIC Implementation n Latch-up Free n High SEU Immunity n Fully Compliant with ESA OBDH, IUB, DBI and RBI Specification n Contains OBDH Bus Modem and RTU Kernel n Supports Bi-directional Data Transfer on Response and Block Transfer Bus MA28139 OBDH Bus Terminal Replaces June 1999 version, DS3592-5.0 DS3592-6.0 January 2000

In RT mode, power up resets the OBT and causes it to deselect both busses. Two watchdog counters monitor the Nominal l-bus and the Redundant l-bus. If either bus becomes active, that bus will be selected. If the selected bus stops, the OBT watchdog times out and resets both the OBT and the user. If both busses become active, the Nominal bus will be selected in preference to the Redundant one. A change in bus selection will always result in the OBT and the user being reset. Responses from the user are always returned on the selected bus. Setting ‘SIMUL’ high causes both BATs to drive both the Nominal and the Redundant busses irrespective of the current bus selection. The time-out period may be set to any desired number of bits by varying the ‘LOSC’ frequency. The OBT derives all timing from, and is synchronous with, the selected l-bus. The OBT demodulates the l-bus to the DBI and decodes commands to the IUB. The CTpRTn mode pin causes the modem circuits and the RTU Kernel to be either cascade or isolated. If CTpRTn is low (RT mode), the RIRSYNC, CLK, DATA and VAL signals are routed to the RTU Kernel and the associated pins act as outputs; responses from the RTU Kernel are ORed with those from the external RRTDATA and RRTEN inputs and can be independently monitored on the DATARRT and ENRRT pins. In this mode any reset caused by the Clock Detector watchdogs is also combined with the power up reset input. If CTpRTn is high (CT mode), the modem and RTU Kernel functions are isolated to permit the device to be used as either a modem within the CTU or an RTU Kernel interfacing to an external modem where the RIRSYNC, CLK, DATA and VAL pins act as inputs. The right-hand multiplexer bank is switched to the upper position so that the CT drives the OBDH via the CIT and CBT (if used) pins and receives responses/telemetry via the CRR and CBR (if used) pins. Note: in CT mode, BAT1 must be connected to the l-busses. In RT mode, the CITSEL, MOD, CLK, SYNC and INV pins are disabled and the clocks are supplied by the l-bus BAR in response to the selected bus. In CT mode, the Clock Detector is functional and drives the TlMEOUTn pin but is unable to cause internal reset on time-out; in this mode the CT must supply all clocks and select the operational bus. The changes depending upon selection of RT mode or CT mode with the CTpRTn pin are defined in the table below: Functional Signal CT Mode Source RT Mode Source (CTpRTn = ‘1’) (CTpRTn = ‘0’) BAT1, 2 modulation clock CITMOD input pin Recovered R2F BAT1, 2 data clock CITCLK input pin Recovered RIRCLK BAT1 data input RRTDATA input pin RRTDATA OR DATARRT (RTU Kernel) BAT1 tx enable ‘1’ RRTEN OR DATAEN (RTU Kernel) BAT1 sync code tx enable CITSYNC input pin ‘0’ BAT1 bit invalidate tx enable CITINV input Pin ‘0’ BAT1, 2 bus selection CITSEL and SIMUL input pins Detected active bus and SIMUL input pin BAT2 data input RBTDATA input Pin RBTDATA input pin BAT2 tx enable RBTEN input pin RBTEN input pin BAT1, 2, BAR1, 2, 3 reset MRSTn input pin TlMEOUTn AND MRSTn input pin RIRSYNC, CLK, DATA, outputs inputs VAL pin direction BAT/BAR and RTU Kernel separated coupled coupling

Figure 4: Architecture MODEM Modulation Waveforms are compliant with ESA document THB/Apo/KZ/1386/av. Waveforms indicating the operation of BAT1, 2 and BAR1, 2, 3 in both the CT and RT modes are shown in Figures 5 to 8. Note: Switches in lower position - RT mode Switches in upper position - CT mode BUS TIME OUT SIMUL CT MODE RESET IUB SYNC, CLK, DATA, VAL RIR SEL MOD CLK SYNC INV DATA EN CLK, DATA, VAL INIT DATA EN CLK, DATA, VAL INIT RBR/ CBR RBT/CBT RRR/CRR CIT RRT DBI BAR1 I-BUS RX BAT1 BAR2 R-BUS RX BAT2 BT-BUS TX BAR3 BT-BUS RX MA28139 OBT CLK OBDH CLOCK DETECTOR WATCHDOG NOMINAL BUS #1 REDUNDANT BUS #2 I R BT I R BT NIDS1/2n, RIDS1/2n RR1-4, NRE, RRE NRDS1/2n RRDS1/2n BR1-4, NBE, RBE NBDS1/2n, RBDS1/2n R-BUS TX (RT MODE) I-BUS TX (CT MODE) TA0-5 TAV DATARRT ENRRT RTU KERNEL BUS 1/2 ACTIVE LOSC OPEN

Figure 5: CT Mode Bus Adaptor Transmitter Waveforms Note 1: Raising CITSYNC for one bit period causes an invalid bit, a valid bit and another invalid bit to be modulated. The exact pattern is determined by RRTDATA; ‘110’ gives the classic H0H0H0L0L0L0 sync pattern. Note 2: Valid Litton ‘1’ modulated. Note 3: Valid Litton ‘0’ modulated. Note 4: Invalid Litton ‘0’ modulation is caused by raising CITINV for one bit period. Note 5: Raising CITINV for more than one bit period only causes one invalid bit to be modulated. Note 6: BAT2 operation is similar, but SYNC and INV are not available.

Figure 6: RT Mode Bus Adaptor Transmitter Waveforms Note: BAR2 and BAR3 operation are similar with different nomenclature.

Figure 7: RT Mode Bus Adaptor Receiver Waveforms Note 1: H0H0H0L0L0L0 sync pattern detected and resets phase of RIRCLK. Note 2: Valid Litton ‘1’ detected. Note 3: Valid Litton ‘0’ detected. Note 4: Invalid Litton ‘0’ detected. Note 5: Further invalid bits do not affect RIRVAL - it will rise as RIRSYNC rises. Note 6: BAR2 and BAR3 operation is similar, but SYNC is not available and RRRINIT and RBRINIT are provided. RIDS2n

Figure 8: BAR2 Bus Adaptor Receiver Waveforms Note 1: RRRINIT asynchronously resets RRRVAL to clear errors detected in the previous response. Note 2: Valid Litton ‘1’ detected. Note 3: Valid Litton ‘0’ detected. Note 4: Invalid Litton ‘0’ detected. Note 5: Further invalid bits do not affect RRRVAL - it will rise as RRRINIT rises. Note 6: BAR3 operation is similar, but is intended to support Block Transfer - RBRINIT hence occurs once per block. Note 7: Operation of BAR2 and BAR3 does not depend on RT mode or CT mode, except for bus selection. RIDS2n

The Clock Detector architecture is shown in Figure 9; a separate channel is essentially provided for each of the Nominal and Redundant Interrogation busses. Associated waveforms are shown in Figure 10. Figure 9: Clock Detector Architecture Each channel contains an Edge Detector and a 5-bit Watchdog Counter which respond only to high-to-low transitions on their respective Interrogation bus DS1n inputs. A common Bus Usage Detection circuit is used to generate time- out pulses (used for internal and external reset) and bus selection signals from the results of the watchdogs. The local oscillator input, LOSC, is divided and decoded to generate an active low reset and an active high sample clock. When applied to both input Edge Detectors, these signals permit input high-to-low transitions to be detected for one LOSC cycle in every two (between the reset ↓ and sample clock ↑). Once such transitions have been detected by a sample clock, the associated watchdog counter is reset. The MSB of each watchdog counter is used as an indication of its bus’s status - active or inactive. Should the watchdog counter overflow (i.e. its MSB be set to 1), the associated bus will be considered inactive. The status of the Nominal and Redundant Interrogation busses is used to determine internal bus selection for the modulation of Response and Block Transfer data in the device’s RT mode. If neither bus is considered active, the TlMEOUTn pin will be held low and RT mode reception of all 3 busses will be inhibited. If one bus is considered active, RT mode reception will occur on the same set of bus circuits (redundancy) as the active Interrogation bus. If both busses are considered active, RT mode reception from the Nominal set of bus circuits will be performed. RT mode transmission will always occur on the same set of bus circuits (redundancy) as selected for reception unless the SIMUL pin is held high, in which case transmission will occur simultaneously on both the Nominal and Redundant busses. Both watchdog counters are fully set at power up to mark both busses as inactive - in this way, a missing LOSC input will not cause inactive busses to be deemed active. For a single detected input transition, 17.5 to 18.5 LOSC cycles will elapse before the relevant bus is considered inactive. If near-instantaneous Nominal-to-Redundant or Dual- to-Redundant bus handover occurs, the change-over will be delayed by 18 to 19 LOSC cycles, in order to preserve the priority of the Nominal bus. If near-instantaneous Redundant- to-Nominal or Redundant-to-Dual bus handover occurs, the change-over will occur after 1.5 to 2.5 LOSC cycles since the Nominal bus takes priority. In either of these cases, a 1 LOSC cycle TlMEOUTn pulse is always generated to ensure that internal reset occurs. The frequency of the local oscillator may be varied to make the nominal time-out period of 17.5 LOSC cycles correspond to any desired number of (missing) bits on the Interrogation bus. Variation of the duty cycle does not vary the time-out period. After 16 LOSC cycles without detected input transitions, the associated watchdog times-out and is detected on the next LOSC ↑ edge; the generation of a TlMEOUTn pulse and reset are then inevitable. For proper Clock Detector operation, (at least) one high-to- low input transition must be detected within a period of 16 LOSC cycles of the last such detection, but transitions made during alternate LOSC cycles (the phase is difficult to predict) will not be detected. Local oscillator clock signals which are harmonically-related to the modulation clock by an integer ratio are thus a cause for concern, although this problem is perhaps only likely to occur in experimental set-ups.

Figure 10: MA28139 Clock Detector Operation Note: If both busses are determined by their watchdogs to be active (as indicated above by their status), the Nominal Bus will always be used by the Bus Adaptor Transmitter and Receiver circuits instead of the Redundant Bus.

The requirement to respect set-up and hold times for the capture of the Edge Detector outputs by the LOSC high-to-low transition means that LOSC signals which are harmonically- related to the Litton modulation clock but whose phase can not be controlled can never be guaranteed to provide reliable operation. For asynchronous local oscillator signals, there will be no concern if we are simply able to place two or more Litton DSn high-to-low edges into each LOSC cycle, so that: τ MOD ≤ τLOSC - tSU - tHOLD and the time-out period of 16 τLOSC is hence approximately 8 bit periods or more. However, suppose that the periods of the modulation clock and the local oscillator clock are such that the relationship between them is: τ MOD = m τLOSC where m is a positive integer. In order to respect the setup and hold times, tSU + tHOLD respectively, between the DSn ↓, and LOSC ↓ edges, it is necessary to avoid such harmonic relationships; it can be shown that around these spot frequencies it is necessary to ensure that either: w τ MOD ≥ x τLOSC + tSU + tHOLD or y τMOD ≤ z τLOSC - tSU - tHOLD where the integer constants w, x, y and z are given in the table below. Since two modulation clock cycles occur per bit, the time- out period at these harmonics will then be: 16 τLOSC ≈ 16 τMOD / m ≈ 8 / m bit periods. m w x y z Approx. time-out period (bit periods) 1 1 51 51 71 7 8 27 1 5 8 1 5 4 3 5 15 5 15 2.67 43 1 3 4 1 5 2 5 3 15 3 15 1.6 6 2 13 2 11 1.33 71717 1.14 8192 1 5 1 91919 0.88 10 1 11 1 9 0.8 11 1 11 1 11 0.73 12 1 13 1 11 0 67 13 1 13 1 13 0.62 14 1 15 1 13 0.57 15 1 15 1 15 0.53 In summary, slow local oscillator clocks which cause relatively long timeout periods ≥ 8 bit periods are not considered a problem; very long time-outs can be reliably implemented. For shorter time-out periods, however, it is necessary to avoid harmonic relationships between the Litton modulation clock and the local oscillator. The simplest practical method for avoiding such relationships would be to arrange for the ratio n = τ MOD / τLOSC to have a half-integer value such that n = 0.5, 1.5, 2.5, ...using an independent crystal oscillator if necessary.

The Central Terminal Unit controls timing, commands and telemetry to all subsystems on the OBDH bus. ESA TTC-B-01 specifies the OBDH to be 2 redundant sets (Nominal and Redundant) of 2 twisted pairs (Interrogation and Response bus) plus an optional redundant 3rd twisted pair (Block Transfer bus), Litton modulated (self clocking with parity on each bit), balanced transformer coupled for less than 1 error in 100 million bits on a 25 metre bus. The data rate is nominally 500K Bits/sec although the chip itself supports up to 5MBits/ sec. The OBT is transformer coupled with adjustable reference and threshold levels as shown below. Litton more positive than V th+ makes discriminator signal NIDS1n low. Litton more negative than Vth- makes NIDS2n low. OBT RR1n, RR2, RR3n, RR4 control 4 switches which drive the bus with bipolar Litton code when enabled. For clarity redundancy is not shown below: TTC-B-01 also specifies the IUB. The OBT supplies specified clocks, memory load address for ML data (or channel address for mode command) and responds on the R bus with a 13 zeroes response as acknowledgement. If the command requires data aquisition, the OBT responds with a 13 or 21 bit response containing 8 or 16 bits (respectively) of user data, controlling external ADC as required. Note: Connections to redundant OBDH busses omitted for clarity. Figure 11: OBDH to IUB interface +5V I-BUS OBT+ CLOCKS ML ADDRESS ML DATA CHANNEL ADDRESS MODE COMMAND ANALOG TO DIGITAL CONVERTER CONTROLS IUB ENABLE GND +5V GND REF R-BUS DATA Vth+ Vth- NIDS1n NIDS2n RR1n RR3n RR2 RR4

RTU KERNEL PROTOCOL VIOLATIONS Some commands to the RTU Kernel cannot be completed within one Interrogation period (or “slot”) because of the need to provide a slow external interface as defined in ESA standard TTC-B-01. These are commands for 16-bit Digital Serial Acquisition (S16) and 16-bit Memory Load (ML). In addition, it is also possible to inhibit On/Off commands by pin configuration. Consequently: n a Memory Load command cannot be followed by another Memory Load command in the next Interrogation; the second command of such a sequence will be ignored, n a 16-bit Digital Serial Acquisition (S16) cannot be followed by another acquisition or command in the next Interrogation; the second command of such a sequence will be ignored, n a Long On/Off command will be ignored if the On/Off command Inhibit input pin, OOINH, is high. RTU KERNEL MODE DEFINITIONS The mode field contained in bits 19 to 22 of the Interrogation is decoded during acquisition commands to drive one of the MOSC, MOLC, MOHL, MOBT, MODBL, MODS8, MODS16, MOANS or MOAND outputs. Mode decoding is an extension of that defined in ESA standard TTC-B-01 Table 7.1 and is shown in Table 1 below: Note that in all MODE Dependent Command and Acquisition Interrogations, bits 23 to 30 of the Interrogation are output as an 8 bit channel address on CHADD(0:7). ESA standard TTC-B-01, p.110 specifies a 7 bit channel address in bits 27 to 29, leaving bit 30 as Reserved. For complete compliance with this standard, CHADD(7) should be disregarded and CHADD(0:6) only should be used. The signals generated by the RTU Kernel during 8-bit Single-Ended and 8-bit Double-Ended Analog Data Acquisitions are intended for connection to an 8-bit serial ADC module. The outputs PC, ANCLK, SOC and SH are intended to provide ADC power control, conversion clock, start of conversion pulse and sample/hold control respectively. RTU Kernel BroadCast Pulse and BCP Validity Waveforms are shown in Figure 12. RTU Kernel Memory Load Command Waveforms are shown in Figure 13. RTU Kernel MODE Dependent Command and Acquisition Waveforms are shown in Figures 14 - 17. Mode Code Associated Bit 19 Bit 20 Bit 21 Bit 22 Function Output Pin 0 0 0 0 Unused - 0 0 0 1 Short Switch Closure On/Off Command MOSC 0 0 1 0 Long Switch Closure On/Off Command MOLC 0 0 1 1 High Power Switch Closure On/Off Cmd MOHL 0 1 0 0 Unused - 0 1 0 1 Unused - 0 1 1 0 Unused - 0 1 1 1 Block Transfer Command MOBT 1 0 0 0 8-bit Digital Bi-Level Data Acquisition MODBL 1 0 0 1 Unused - 1 0 1 0 16-bit Serial Digital Data Acquisition MODS16 1 0 1 1 8-bit Serial Digital Data Acquisition MODS8 1 1 0 0 8-bit Single-Ended Analog Data Acquisition MOANS 1 1 0 1 Unused - 1 1 1 0 8-bit Double-Ended Analog Data Acquisition MOAND 1 1 1 1 Unused - Table 1: RTU Kernel Mode Definitions

Figure 12: BroadCast Pulse and BCP Validity Waveforms Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL BCP(1:4) BCPVAL Note 1: Bit 6 of the Interrogation will be interpreted as BCP(4) if (EXTFMT = 0); if (EXTFMT = 1), the BCP (4) output will be 0 and bit 6 will be interpreted as TA(0). Note 2: (RIRVAL = 0) (presumably because of bad Interrogation length or received Litton coding errors detected by the modem), bad received parity in bit 31 of the Interrogation or wrong Interrogation length will both cause the Interrogation to be rejected and will set BCPVAL = 0. Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL BCP(1:4) BCPVAL = BCP(4) or TA(0)1

MLADD(0:4) MLDATA DATARRT ENRRT Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK MLADD(0:4) MLDATA DATARRT ENRRT Figure 13: Memory Load Command Waveforms Note 1: One Memory Load command takes 2 Interrogations to complete. Consecutive Memory Load commands are hence not possible and form a protocol violation. The second Memory Load command of such a sequence will be rejected. Note 2: For a Memory Load command to be decoded, the evaluated Memory Load Address must be non-zero. An evaluated Memory Load Address of zero implies data aquisition. Note 3: The Memory Load Address which is evaluated for decoding and addressing usage may vary from 3 to 5 bits. If (EXTMLA1 = 1) and (EXTMLA2 = 0), the Memory Load Address field is extended to 4 bits and bit 11of the Interrogation will be treated as MLA(1). If (EXTMLA2 = 1), the Memory Load Address field is extended to 5 bits and bits 10 and 11of the Interrogation will be treated as MLA(0:1). Any Interrogation bits treated as Extended Memory Load Address bits will not be treated as Terminal Address bits; this facility is intended for 2x or 4x size expansion provided that up to 4 consecutive Terminal Addresses can be used. Note 4: The Memory Load command response is always 13-zeros. = BCP(4) or TA(0) = TA(4:5) or MLA(0:1) 1 2

Figure 14: 8-Bit Digital Serial and 8-Bit Digital Bi-Level Acquisition Waveforms Note 1: For any acquisition command to be decoded, the evaluated Memory Load Address must be zero. An evaluated Memory Load Address of non-zero does not imply data acquisition. Note 2: The Memory Load Address which is evaluated for decoding and addressing usage may vary from 3 to 5 bits. If (EXTMLA1 = 1) and (EXTMLA2 = 0), the Memory Load Address field is extended to 4 bits and bit 11 of the Interrogation will be treated as MLA(1). If (EXTMLA2 = 1), the Memory Load Address field is extended to 5 bits and bits 10 and 11of the Interrogation will be treated as MLA(0:1). Any Interrogation bits treated as Extended Memory Load Address bits will not be treated as Terminal Address bits; this facility is intended for 2x or 4x size expansion provided that up to 4 consecutive Terminal Addresses can be used. Note 3: The 8-bit Digital Serial and 8-bit Digital Bi-Level Acquisition command responses are always 13 bits in length; the Destination Address is simply copied from the Interrogation into the Response. Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) MODS8 or DIGIN DATARRT ENRRT MODBL Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) MODS8 or DIGIN DATARRT ENRRT MODBL

Figure 15: 16-Bit Digital Serial Acquisition Waveforms Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) MODS16 DIGIN DATARRT ENRRT Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) MODS16 DIGIN DATARRT ENRRT Note 1: One 16-bit Digital Serial Acquisition command takes 2 Interrogations to complete. A succeeding Acquisition or Switch Closure command of any type is hence not possible and forms a protocol violation. The second command of such a sequence will be rejected. Note 2: For any acquisition command to be decoded, the evaluated Memory Load Address must be zero. An evaluated Memory Load Address of non-zero does not imply data acquisition. Note 3: The Memory Load Address which is evaluated for decoding and addressing usage may vary from 3 to 5 bits. If (EXTMLA1 = 1) and (EXTMLA2 = 0), the Memory Load Address field is extended to 4 bits and bit 11 of the Interrogation will be treated as MLA(1). If (EXTMLA2 = 1), the Memory Load Address field is extended to 5 bits and bits 10 and 11 of the Interrogation will be treated as MLA(0:1). Any Interrogation bits treated as Extended Memory Load Address bits will not be treated as Terminal Address bits; this facility is intended for 2x or 4x size expansion provided that up to 4 consecutive Terminal Addresses can be used. Note 4: The 16-bit Digital Serial Acquisition command response is always 21 bits in length; the Destination Address is simply copied from the Interrogation into the Response.

CHADD(0:7) MOANS PC ANCLK SOC SH ANSIN DATARRT FNRRT or MOAND Note 1: For any acquisition command to be decoded, the evaluated Memory Load Address must be zero. An evaluated Memory Load Address of non-zero does not imply data acquisition. Note 2: The Memory Load Address which is evaluated for decoding and addressing usage may vary from 3 to 5 bits. If (EXTMLA1 = 1) and (EXTMLA2 = 0), the Memory Load Address field is extended to 4 bits and bit 11 of the Interrogation will be treated as MLA(1). If (EXTMLA2 = 1), the Memory Load Address field is extended to 5 bits and bits 10 and 11of the Interrogation will be treated as MLA(0:1). Any Interrogation bits treated as Extended Memory Load Address bits will not be treated as Terminal Address bits; this facility is intended for 2x or 4x size expansion provided that up to 4 consecutive Terminal Addresses can be used. Note 3: The 8-bit Analog Single-Ended and 8-bit Analog Double-Ended Acquisition command responses are always 13 bits in length; the Destination Address is simply copied from the Interrogation into the Response. Figure 16: 8-Bit Analog Single-Ended and 8-Bit Analog Double-Ended (Serial) Acquisition Waveforms

CHADD(0:7) MOANS PC ANCLK SOC SH ANSIN DATARRT FNRRT or MOAND Figure 16 continued

Figure 17: Short-Command, Long-Command and High-Level Switch Closure and Block Transfer Command Waveforms Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) DATARRT ENRRT MOSC, MOLC, MOHL or MOBT Bit Position RIRSYNC RIRCLK RIRDATA RIRVAL IRCLK TRCLK CTCLK CHADD(0:7) DATARRT ENRRT MOSC, MOLC, MOHL or MOBT Note 1: The Block Transfer command does not require a Channel Address; CHADD(0:7) is set therefore to zero. Note 2: For any acquisition command to be decoded, the evaluated Memory Load Address must be zero. An evaluated Memory Load Address of non-zero does not imply data acquisition. Note 3: The Memory Load Address which is evaluated for decoding and addressing usage may vary from 3 to 5 bits. If (EXTMLA1 = 1) and (EXTMLA2 = 0), the Memory Load Address field is extended to 4 bits and bit 11 of the Interrogation will be treated as MLA(1). If (EXTMLA2 = 1), the Memory Load Address field is extended to 5 bits and bits 10 and 11of the Interrogation will be treated as MLA(0:1). Any Interrogation bits treated as Extended Memory Load Address bits will not be treated as Terminal Address bits; this facility is intended for 2x or 4x size expansion provided that up to 4 consecutive Terminal Addresses can be used. Note 4: The Short-Command, Long-Command, High-Level Switch Closure and Block Transfer command responses are always 13-zeroes.

THE ESA ON-BOARD DATA HANDLING (OBDH) BUS The dual redundant OBDH bus is connected to the OBT bus interface via an input descriminator and an output bridge driver circuit. These convert between the bipolar LITTON code and the standard CMOS inputs and outputs of the IC. The OBDH bus is divided into three parts: A. INTERROGATION BUS (I BUS) This bus is used to transfer data from the CT to the RTs, as commands of 32 bit words, each bit being modulated according to the Litton scheme shown in Figure 18. Each Interrogation (or command) “slot” comprises 3 Sync bits, 3 or 4 BroadCast Pulses, 5 or 6 Terminal Address bits, 4 Destination Address bits, 16 Data bits and a Parity bit. B. RESPONSE BUS (R BUS) This bus is used to send data from the RTs to the CT, (can be used by RTs to receive data). Each response word comprises the 4 Destination Address bits sent in the corresponding Interrogation, either 8 or 16 Data bits from the user (8 bits unless a 16 bit acquisition was requested and 8 zeros if no response data is required) and a single Stop bit (used to ensure data is fully clocked through bus modems and 0 by convention). C. BLOCK TRANSFER BUS (BT BUS) Used to transfer blocks of data between the CT and RTs, in either direction, as a contiguous block or stream of data bits. Figure 18: Litton Coded Data logical "1" logical "0" invalid logic "1" invalid logic "0" high - low - 0v - high - 0v - high - low - 0v - low - 0v - invalid logic "1" high - 0v - logical "1" invalid logic "0" low - Synchronisation Pattern FASTER OBDH/DBI COMPATIBLE NETWORKS With analog components the OBT can interface any equipment to the specified ESA OBDH bus at the nominal data rate of 0.5 Mbps. Contract 5352 proved that analog components limit OBDH data rate to 2 Mbps maximum. But OBTs work to over 5 Mbps (10MHz with 2 clocks/bit Litton coded). OBTs may be directly networked via digital bus drivers/receivers, (eliminating analog components) using Litton coded 4 wire (R2/DS1 and R4/DS2) busses (see OBDH application note 1). MSS made a 3 metre optical OBDH network for the Pegasus ion source. DBIs may be directly connected but will not be Litton coded with Parity on every bit, or exhibit modulation and demodulation delays.

CONNECTIONS TO THE OBDH I, R AND BT BUSSES (SUGGESTED SCHEMES ONLY) TRANSMITTER Two OBDH bus driver schemes based on complementary and N-channel enhancement-mode FETs are shown. Current-limiting and protection resistors may be employed to prevent damage under short-circuit. Latching and/or non-latching relays may be used to provide isolation from the bus when a redundant circuit is unused or unpowered. NPN and/or PNP bipolar junction transistors may also be employed in place of FETs. Redundancy can be handled in channels (as shown) or by applying cross-strapping between the transformers and the drivers. This implementation generates ‘active ground’ pulses where the transformer is shorted out (by conduction of the two lower FETs) while the bus driver is enabled to reduce ringing, bus echoes, etc. Using XR2 in place of XR3n and XR4 in place of XR1n will not cause ‘active zeros’ to be driven. XR4 XR2 XR3n XR1n XR4 XR2 XR3n XR1n Figure 19: Conceptual OBDH Bus Driver Scheme

Figure 20: Conceptual OBDH Bus Window Discriminator Scheme RECEIVER Two OBDH bus window discriminator schemes, based on balanced and unbalanced techniques are shown. Current-limiting and protection resistors may be employed to prevent damage under short-circuit. Latching and/or non-latching relays may be used to provide isolation from the bus when a redundant circuit is unused or unpowered. Noise filtering and the effects of bus loading should be considered. Redundancy can be handled in channels (as shown) or by applying cross-strapping between the transformers and the receivers.

DC CHARACTERISTICS AND RATINGS Parameter Min Max Units Supply Voltage -0.5 7 V Input Voltage -0.3 V DD +0.3 V Current Through Any Pin -20 +20 mA Operating Temperature -55 +125 °C Storage Temperature -65 +150 °C Note: Stresses above those listed may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these conditions, or at any other condition above those indicated in the operations section of this specification, is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2: Absolute Maximum Ratings Parameter Supply Voltage CMOS input high voltage CMOS input low voltage Output high voltage Output high voltage Input Pull-down current Input Pull-down current Input Pull-up current Input Pull-up current Input leakage current Output leakage current Output leakage current Static Power supply Current Dynamic Power supply Current Conditions I OH = -1.0mA IOL = 4.0mA VDD = 5.5V, VIN = VSS VDD = 5.5V, VIN = VDD VDD = 5.5V, VIN = VSS VDD = 5.5V, VIN = VDD VDD = 5.5V, VIN = VSS or VDD VDD = 5.5V, VOUT = VSS VDD = 5.5V, VOUT = VDD VDD = 5.5V f = 1MHz, VDD = 5.5V Typ. 5.0 0.02 Symbol VDD VIH VIL VOH VOL IPDL IPDH IPUL IPUH IL IOZL IOZH IDD1 IDD2 Min. 4.5 0.8VDD VSS VDD - 0.5 -25 -400 -25 -10 -30 Units V V V V V µA µA µA µA µA µA µA mA mA Max. 5.5 VDD

0.2 VDD

0.4 400 -25 400 Notes: 1. VDD = 5V ±10% over full temperature range. 2. Total dose radiation not exceeding 105 Rads(Si). 3. Mil-Std-883, method 5005, subgroups 1, 2, 3. 4. All outputs are suitable for TTL/CMOS drive. 5. Electro-Static Discharge protection is provided for all pins. 6. Internal pull-up or pull-down resistors should not be relied upon for proper operation and/or termination of input levels under all operating conditions without prior consultation with GPS. 7. Input and output leakage measurements are guaranteed but not tested at -55°C. Table 3: DC Characteristics

No. Parameter Condition Min. Max. Units T1 CITMOD to RR1n, RR2, RR3n, RR4, BR1n, CTU mode - 45 ns BR2, BR3n, BR4 T2 CITMOD to NRE, RRE, NBE, RBE CTU mode - 55 ns T3/ CITSYNC, CITINV to CITCLK ↑ (setup/hold) CTU mode 10 - ns T3a T4/4a RRTDATA to CITMOD ↓ (setup/hold) CTU mode 10 - ns T5/5a RBTDATA to CITMOD ↓ (setup/hold) CTU mode 10 - ns T6/6a RBTEN to CITMOD ↑ (setup/hold) CTU mode 10 - ns T7/7a CITCLK to CITMOD ↑ (setup/hold) CTU mode 10 - ns T8 NIDS1n, NIDS2n, RIDS1n, RIDS2n to RR1n RTU mode - 55 ns RR2, RR3n, RR4, BR1n, BR2, BR3n, BR4 T9 NIDS1n, NIDS2n, RIDS1n, RIDS2n to NRE RTU mode - 75 ns RRE, NBE, RBE T10/ RRTDATA to NIDS1n, NIDS2n, RIDS1n, RTU mode 10 - ns T10a RIDS2n ↓ (setup/hold) T11/ RBTDATA to NIDS1n, NIDS2n, RIDS1n, RTU mode 10 - ns T11a RIDS2n ↓ (setup/hold) T12 RRTEN to NIDS1n, NIDS2n, RIDS1n, RIDS2n ↑ setup RTU mode 0 - ns T12a RRTEN to NIDS1n, NIDS2n, RIDS1n, RIDS2n ↑ hold RTU mode 35 - ns T13 RBTEN to NIDS1n, NIDS2n, RIDS1n, RIDS2n ↑ setup RTU mode 0 - ns T13a RBTEN to NIDS1n, NIDS2n, RIDS1n, RIDS2n ↑ hold RTU mode 35 - ns Table 4: Bus Adaptor Transmitter Characterisation No. Parameter Condition Min. Max. Units T14 NIDS1n, NIDS2n, RIDS1n, RIDS2n ↓ to RTU mode - 80 ns RIRSYNC, RIRCLK, RIRDATA, RIRVAL valid T15 NRDS1n, NRDS2n, RRDS1n, RRDS2n ↓ to RTU mode - 55 ns RRRCLK, RRRDATA valid T16 NBDS1n, NBDS2n, RBDS1n, RBDS2n to RTU mode - 55 ns RBRCLK, RBRDATA valid T17 NRDS1n, NRDS2n, RRDS1n, RRDS2n ↓ to RTU mode - 55 ns RRRVAL ↓ T18 NBDS1n, NBDS2n, RBDS1n, RBDS2n to RTU mode - 55 ns RBRVAL ↓ T19 RRRINIT to RRRVAL ↑ RTU mode - 30 ns T20 RBRINIT to RBRVAL ↑ RTU mode - 30 ns T21 NIDS1n, NIDS2n, RIDS1n, RIDS2n pulse RTU mode 12 - ns width low (min.) T22 NRDS1n, NRDS2n, RRDS1n, RRDS2n pulse RTU mode 12 - ns width low (min.) T23 NBDS1n, NBDS2n, RBDS1n, RBDS2n pulse RTU mode 12 - ns width low (min.) Table 5: Bus Adaptor Receiver Characterisation

No. Parameter Condition Min. Max. Units T24 LOSC ↓ to NIDS1n, NIDS2n, RIDS1n, CTU mode or RTU mode 10 - ns RIDS2n ↓ (hold max.) T25 LOSC ↓ to NIDS1n, NIDS2n, RIDS1n, CTU mode or RTU mode 15 - ns RIDS2n ↓ (setup max.) T26 LOSC ↑↓ to TIMEOUTn valid CTU mode or RTU mode - 55 ns Timeout period = 16τLOSC CTU mode or RTU mode Guaranteed, not measured Redundant to Dual or Redundant to Nominal CTU mode or RTU mode Guaranteed, not measured bus changeover TIMEOUTn low reset period = τ LOSC Table 6: Clock Detector Characterisation No. Parameter Condition Min. Max. Units T27 RIRCLK ↓ to BCP(1:4), BCPVAL valid CTU mode - 70 ns T28 RIRCLK ↓ to MLADD(0:4) CTU mode - 80 ns T29 RIRCLK ↓ to MLDATA CTU mode - 80 ns T30 RIRCLK ↓ to CHADD CTU mode - 75 ns T31 RIRCLK ↓ to MOSC, MOLC, MOHL, MOBT, CTU mode MODBL, MODS16, MODS8, MOANS, - 70 ns MOAND valid T32 RIRCLK ↓ to IRCLK, CTCLK, TRCLK valid CTU mode - 70 ns T33 RIRCLK ↓ to PC, ANCLK, SOC, SH valid CTU mode - 70 ns T34 RIRCLK ↓ to DATARRT, ENRRT valid CTU mode - 55 ns T35 ANSIN to RIRCLK ↑ setup RTU mode 0 - ms T35a ANSIN to RIRCLK ↑ hold RTU mode 30 - ns T36 NIDS1n, NIDS2n, RIDS1n, RIDS2n ↓ to RTU mode - 75 ns DATARRT, ENRRT Note 1:RTU mode timing parameters not explicitly stated will be lower than the sum of the appropriate parameters for the RTU Kernel, BAR1 and BAT2. Parameters T34 and T36 above may be used to estimate the difference in timing between CTU mode (i.e. where the RTU Kernel, BAR1 and BAT2 are not coupled together) and RTU mode usage (i.e. where those components are coupled together). Note 2:Configuration pins such as TA(0:5), EXTFMT, EXTMLA1 and EXTMLA2 and MRSTn are not considered here because they do not need to be dynamically changed. Note 3:V DD = 5V ±10% over full temperature range. VOH = VOL = VDD /2, VIL = VSS , VIH = VDD , CL = 50pF. Note 4:Total dose radiation not exceeding 105 Rads (Si). Note 5:Tables 4, 5, 6 & 7 contain Mil-Std-883, method 5005, subgroups 9, 10, 11. Table 7: RTU Kernel Characterisation Conditions VI = 0V VI/O = 0V Min. Typ. Max. Note 1: TA = 25˚C and f = 1MHz. Data obtained by characterisation or analysis; not routinely measured. Table 8: Capacitance Units pF pF Parameter Input Capacitance Output Capacitance Symbol C IN C OUT

VDD = 4.5 - 5.5V, FREQ = 1 MHz VIL = VSS , VIH = VDD , VOL = VOH = VDD /2 TEMP = -55˚C to +125˚C, GPS Pattern Set Mil-Std-883, method 5005, subgroups 7, 8A, 8B Table 9: Functionality Symbol FT Parameter Functionality Subgroup Table 10: Definition of Subgroups Definition Static characteristics specified in Table 3 at +25˚C Static characteristics specified in Table 3 at +125˚C Static characteristics specified in Table 3 at -55˚C Functional characteristics specified in Table 9 at +25˚C Functional characteristics specified in Table 9 at +125˚C Functional characteristics specified in Table 9 at -55˚C Switching characteristics specified in Tables 4 to 7 at +25˚C Switching characteristics specified in Tables 4 to 7 at +125˚C Switching characteristics specified in Tables 4 to 7 at -55˚C

Figure 21: OBT Schematic OBT MLDATA MLADD (0:4) IRCLK CTCLK TRCLK CHADD (0:7) MOSC MOLC MOHL MOBT MODBL MODS16 MODS8 MOANS MOAND PC ANCLK SOC SH DIGIN ANSIN TAV BCP (1:4) BCP VAL ENRRT DATARRT OOINH EXTMLA2 EXTMLA1 EXTFMT TA (0:5) DATA TO USER CLOCKS TO USER MODE ADDRESS TO USER IUB COMMAND TYPE ADC CONTROL IUB DATA ADC DATA USER READY/INHIBIT RESPONSE BROADCAST TIMING INHIBIT MOLC COMMANDS

5 BIT ML ADDRESS

4 BIT ML ADDRESS

6 BIT RT ADDRESS

LOSC TIMEOUT n I-BUS TIMED OUT NIDS1n NIDS2n RIDS1n RIDS2n RR1n RR2 RR3n RR4 NRE RRE NRDS1n NRDS2n RRDS1n RRDS2n BR1n BR2 BR3n BR4 NBE RBE NBDS1n NBDS2n RBDS1n RBDS2n SIMUL CTpRTn MRSTn RIRSYNC RIRCLK RIRDATA RIRVAL RRTDATA RRTEN CITSYNC CITINV CITMOD CITCLK CITSEL RRRCLK RRRDATA RRRVAL RRRINIT RBTDATA RBTEN RBRCLK RBRDATA RBRVAL RBRINIT RESET DIGITAL BUS INTERFACE CT MODE DRIVE BOTH OBDH BUSSES BT-BUS BT-BUS R-BUS R/I-BUS I-BUS OBDH HARDWIRED CONTROL PINS LOCAL OSCILLATOR RT USER BUS CONTROLLER OUTPUT

OBT/IUB PIN LIST AND DESCRIPTIONS No. 131 132 Name IRCLK CTCLK TRCLK MLDATA MLADD0 MLADD1 MLADD2 MLADD3 MLADD4 CHADD0 CHADD1 CHADD2 CHADD3 CHADD4 CHADD5 CHADD6 CHADD7 MOSC MOLC MOHL MOBT MODBL MODS16 MODS8 MOANS MOAND PC ANCLK SOC SH DIGIN ANSIN BCP1 BCP2 BCP3 BCP4 BCPVAL DATARRT ENRRT

Description

Memory load address MSB (Interrogation bit 10) Memory load address Memory load address Memory load address Memory load address LSB (Interrogation bit 14) Channel address 0 (Interrogation bit 23) Channel address 1 Channel address 2 Channel address 3 Channel address 4 Channel address 5 Channel address 6 Channel address 7 (Interrogation bit 30) Mode short command (Interrogation mode bits 19/22 = 1 hex) Switch closure on/off command (mode 2) High power on/off command (mode 3) Mode block transfer (mode 7) Digital bi-level data acquisition (mode 8) 16-bit serial digital data acquisition (mode A) 8-bit serial digital data acquisition (mode B) Single ended analog data acquisition (mode C) Double ended analog acquisition (mode E) Power on to analog-to-digital converter ADC shift clock Start of conversion Sample/hold Digital serial data input Analog serial data input Broadcast pulse 1 (Interrogation bit 3) Broadcast pulse 2 (Interrogation bit 4) Broadcast pulse 3 (Interrogation bit 5) Broadcast pulse 4 (Interrogation bit 6 when extfmt = 0) Broadcast pulses valid Data to RRT when used as RTU kernel Enable RRT when used as RTU kernel Type O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O I (PULL-DOWN) I (PULL-DOWN) O O O O O O O

OBT/DBI PIN LIST AND DESCRIPTIONS No. Name RIRSYNC RIRCLK RIRDATA RIRVAL RRRCLK RRRDATA RRRVAL RRRINIT RRTDATA RRTEN CITSYNC CITINV CITMOD CITCLK CITSEL RBTDATA RBTEN RBRCLK RBRDATA RBRVAL RBRINIT Sync from I-bus or (CT mode) input to RTU kernel Clock from I-bus or (CT mode) input to RTU kernel Data from I-bus or (CT mode) input to RTU kernel Validity from I-bus or (CT mode) input to RTU kernel Clock from R-bus Data from R-bus Validity from R-bus Initialise R-bus receiver Data to R-bus or (CT mode) to I-bus Enable R-bus transmitter (CT mode) sync to I-bus (CT mode) invalid to I-bus (CT mode) modulation to I-bus (CT mode) clock to I-bus (CT mode) select nominal or redundant I-bus Data to BT-bus Enable BT-bus transmitter Clock from BT-bus Data from BT-bus Validity from BT-bus Initialise BT-bus receiver OBT/OBDH PIN LIST AND DESCRIPTIONS No. 111 110 109 108 107 106 105 104 103 102 101 100 Name NIDS1n NIDS2n RIDS1n RIDS2n NRDS1n NRDS2n RRDS1n RRDS2n RR1n RR2 RR3n RR4 NRE RRE NBDS1n NBDS2n RBDS1n RBDS2n BR1n BR2 BR3n BR4 NBE RBE Type I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) O O O O O O I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) I (PULL-UP) (CSCHMITT) O O O O O O BT-bus driver 2 BT-bus driver 3 BT-bus driver 4 Nominal BT-bus enable Redundant BT-bus enable Nominal I-bus Discriminator Signal 1 Nominal I-bus Discriminator Signal 2 Redundant I-bus Discriminator Signal 1 Redundant I-bus Discriminator Signal 2 Nominal R-bus Discriminator Signal 1 Nominal R-bus Discriminator Signal 2 Redundant R-bus Discriminator Signal 1 Redundant R-bus Discriminator Signal 2 R-bus driver 1 R-bus driver 2 R-bus driver 3 R-bus driver 4 Nominal R-bus Enable Redundant R-bus Enable Nominal BT-bus Discriminator Signal 1 Nominal BT-bus Discriminator Signal 2 Redundant BT-bus Discriminator Signal 1 Redundant BT-bus Discriminator Signal 2 BT-bus driver 1 Type O/I (PULL-DOWN) O/I (PULL-DOWN) O/I (PULL-DOWN) O/I (PULL-DOWN) O O O I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) I (PULL-DOWN) O O O I (PULL-DOWN)

OBT CONTROL PIN LIST AND DESCRIPTIONS No. 121 122 123 124 125 126 127 128 129 130 112 Name TA0 TA1 TA2 TA3 TA4 TA5 EXTFMT EXTMLA1 EXTMLA2 OOINH TEST SIMUL CTpRTn MRSTn LOSC TIMEOUTn TAV Type I I I I I I I I I I I I (PULL-DOWN) I (PULL-UP) I (PULL-DOWN) (CSCHMITT) I (CSCHMITT) O I (PULL-DOWN) Terminal Address bit 0 (MSB = I-bus bit 6) Terminal Address bit 1 Terminal Address bit 2 Terminal Address bit 3 Terminal Address bit 4 Terminal Address bit 5 Extended format Enable Extended Memory Load Address 1 Enable Extended Memory Load Address 2 Enable On/Off INHibit of MOLC commands Tie to Ground (this input for test purposes only) Simultaneously drive both busses CT mode when high, RT mode when low Master reset when low Oscillator from user to drive OBT timeout Low when I-bus timeout Terminal available (take low to disable responses from RTU kernal) OBT POWER SUPPLY DISTRIBUTION PINS No. 55, 113 14, 47, 80 Name VDD VSS Type P P Positive supply nominally +5 volts. Connect both pins. Power and signal ground. Connect all pins. Notes: 1. CSCHMITT means CMOS Schmitt-trigger inputs. 2. Internal pull-up or pull-down resistors should not be relied upon for proper operation and/or termination of input levels under all operating conditions without prior consultation with GPS.

Figure 22: Package Dimensions Ref Millimetres Inches A1 1.37 - 1.88 0.054 - 0.074 b 0.23 - 0.33 0.009 - 0.013 c 0.10 - 0.18 0.004 - 0.007 L 6.35 - 7.11 0.250 - 0.280 XG533 117 17 83 51 116 E c AA1 L b e Pin 1 Seating Plane TOP VIEW

132 Lead

Total Dose Radiation Testing For product procured to guaranteed total dose radiation levels, each wafer lot will be approved when all sample devices from each lot pass the total dose radiation test. The sample devices will be subjected to the total dose radiation level (Cobalt-60 Source), defined by the ordering code, and must continue to meet the electrical parameters specified in the data sheet. Electrical tests, pre and post irradiation, will be read and recorded. GEC Plessey Semiconductors can provide radiation testing compliant with Mil-Std-883 test method 1019 Ionizing Radiation (total dose).

ORDERING INFORMATION

For details of reliability, QA/QC, test and assembly options, see ‘Manufacturing Capability and Quality Assurance Standards’ Section 9. Unique Circuit Designator S R Q H Radiation Hard Processing 100 kRads (Si) Guaranteed 300 kRads (Si) Guaranteed 1000 kRads (Si) Guaranteed Radiation Tolerance F N Flatpack (Solder Seal) Naked Die Package Type QA/QCI Process (See Section 9 Part 4) Test Process (See Section 9 Part 3) Assembly Process (See Section 9 Part 2) L C D E B S Rel 0 Rel 1 Rel 2 Rel 3/4/5/STACK Class B Class S Reliability Level MAx28139xxxxx Total Dose (Function to specification)* 1x105 Rad(Si) Transient Upset (Stored data loss) 5x10 10 Rad(Si)/sec Transient Upset (Survivability) >1x10 12 Rad(Si)/sec Neutron Hardness (Function to specification) >1x1015 n/cm2 Single Event Upset** <1x10 -10 Errors/bit day Latch Up Not possible * Other total dose radiation levels available on request ** Worst case galactic cosmic ray upset - interplanetary/high altitude orbit Table 11: Radiation Hardness Parameters

µP MSS OBDH OBT PIU R-bus RBI RBR RBT RIR RRR RRT RT SBC VLSI Application Specific Integrated Circuit Block Transfer Bus CTU mode, block transfer bus, receive CTU mode, block transfer bus, transmit CTU mode, interrogation unit, transmit CTU mode, response bus, receive Central terminal Digital bus interface Digital bus unit European Space Agency Field effect transistor Fault tolerant computer GEC Plessey Semiconductors Interrogation bus Intelligent control unit Internal user bus Remote bus interface (RBI) ASIC OBDH bus terminal (OBT) ASIC Microprocessor Marconi Space Systems - now Matra Marconi Space (MMS) On board data handling OBDH bus terminal (MA28139) Payload interface unit Response bus Remote bus interface (MA28138) RTU mode, block transfer bus, receive RTU mode, block transfer bus, transmit RTU mode, interrogation bus, receive RTU mode, response bus, receive RTU mode, response bus, transmit Remote terminal Single board computer Very large scale integration CUSTOMER SERVICE CENTRES France, Benelux, Italy and Spain Tel: +33 (0)1 69 18 90 00. Fax: +33 (0)1 64 46 54 50 North America Tel: 011-800-5554-5554. Fax: 011-800-5444-5444 UK, Germany, Scandinavia & Rest Of World Tel: +44 (0)1522 500500. Fax: +44 (0)1522 500020 SALES OFFICES France, Benelux, Italy and Spain Tel: +33 (0)1 69 18 90 00. Fax: +33 (0)1 64 46 54 50 Germany Tel: 07351 827723 Tel: (831) 440-1988. Fax: (831) 440-1989 / Tel: (949) 733-3005. Fax: (949) 733-2986. UK, Germany, Scandinavia & Rest Of World Tel: +44 (0)1522 500500. Fax: +44 (0)1522 500020 These offices are supported by Representatives and Distributors in many countries world-wide. © Dynex Semiconductor 2000 Publication No. DS3592-6 Issue No. 6.0 January 2000 TECHNICAL DOCUMENTATION – NOT FOR RESALE. PRINTED IN UNITED KINGDOM HEADQUARTERS OPERATIONS DYNEX SEMICONDUCTOR LTD Doddington Road, Lincoln. Lincolnshire. LN6 3LF. United Kingdom. Tel: 00-44-(0)1522-500500 Fax: 00-44-(0)1522-500550 DYNEX POWER INC. Unit 7 - 58 Antares Drive, Nepean, Ontario, Canada K2E 7W6. Tel: 613.723.7035 Fax: 613.723.1518 Toll Free: 1.888.33.DYNEX (39639) This publication is issued to provide information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. The Company reserves the right to alter without prior notice the specification, design or price of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to the Company's conditions of sale, which are available on request. All brand names and product names used in this publication are trademarks, registered trademarks or trade names of their respective owners. http://www.dynexsemi.com e-mail: power_solutions@dynexsemi.com Datasheet Annotations: Dynex Semiconductor annotate datasheets in the top right hard corner of the front page, to indicate product status. The annotations are as follows:- Target Information: This is the most tentative form of information and represents a very preliminary specification. No actual design work on the product has been started. Preliminary Information: The product is in design and development. The datasheet represents the product as it is understood but details may change. Advance Information: The product design is complete and final characterisation for volume production is well in hand. No Annotation: The product parameters are fixed and the product is available to datasheet specification.