GoetzFIELDS iPDR - TDS SPP/FIELDS Time Domain Sampler Preliminary Design Review Keith Goetz University of Minnesota 1

GoetzFIELDS iPDR - TDS Time Domain Sampler Time Domain Sampler (TDS) is based on previous instruments –Based most recently on STEREO instrument Gathers impulsive events – voltage as a function of time –Centered peaks –Simultaneous sampling on all channels –Fixed sampling rate – 1.92MSa/s which is ~160Mb/s 24x7 throughput –Programmable effective sampling rate –Programmable event duration Events have peaks - triggered –After that, flight software scores event based on programmable criteria –Quality can be adjusted – up or down - after the fact –When telemetry is available (nominally to DCB), best event is sent –When memory is needed (for a new event), worst event is deleted Event selection can be based on quality or not – honesty –Delivered bit-rate is highly programmable – nominally 10kb/s Low rate stream gives peak activity as a function of time 2

GoetzFIELDS iPDR - TDS STEREO snapshot 3

GoetzFIELDS iPDR - TDS STEREO snapshots 4

GoetzFIELDS iPDR - TDS STEREO snapshot 5

GoetzFIELDS iPDR - TDS Dust 6

GoetzFIELDS iPDR - TDS Big Dust 7

GoetzFIELDS iPDR - TDS TDS Heritage Time Domain Sampler (TDS) is based on STEREO instrument Changes - Science –Plasma frequency up from 10’s to 100’s of kHz – shock time scales are faster –TDS samples at ~2MSa/s and ~1MHz Nyquist Programmable down-sampling –Continuous sampling – reduced power supply load variations –Direct deposit – increases duty cycle – eliminates event length limit –Wave-particle correlation with SWEAP Changes – FIELDS System-6 –Added DPU functionality to TDS – similar to STEREO implementation Communicates directly to S/C in addition to DCB Controls MAGi, LNPS2, AEB2 Communicates with SWEAP 8

GoetzFIELDS iPDR - TDS Waveform and Particles 9 Samples Δ t = 500ns CLK ~2MHz V(t) Δ t = 500ns count(t)

GoetzFIELDS iPDR - TDS Waves and Particles 10 Samples Δ t = 500ns V(t) Δ t = 500ns count(t) t = 1,500nst = 2,000nst = 2,500nst = 3,000nst = 3,500nst = 4,000nst = 4,500nst = 5,000ns V = 0mVV = -2mVV = -4mVV = +5mVV = -12mVV = -15mVV = -10mVV = -5mV n = 2n = 4n = 2 n = 7n = 3n = 5

GoetzFIELDS iPDR - TDS TDS Requirements 11 TDS-01 Mission Length –TDS Components must be selected to withstand the environment of SPP for the duration of the mission. TDS-02 Spacecraft Interface Compliance (General) –TDS shall implement the spacecraft interface protocol… TDS-03 Timing from S/C –TDS shall provide latching facility upon detection of the "Virtual 1PPS" S/C timing signal… TDS-04 –Timing from DCB TDS shall provide an electrical interface to the Data Control Board capable of…

GoetzFIELDS iPDR - TDS SWEAP Requirements 12 TDS-05 SWEAP Interface - CDI –TDS shall provide an electrical interface to the SWEAP instrument capable of sending CDI commands, receiving CDI messages: [a] sending Command/Data Interface (CDI) messages to SWEAP; [b] receiving SWEAP status and burst information from SWEAP; [c] sending TDS time-keeping information; [d] sending TDS clock synchronization. TDS-06 SWEAP Interface – Particles –TDS shall provide an electrical interface to the SWEAP instrument capable of: [a] receiving particle count information from SWEAP [b] receiving particle synchronization and state information from SWEAP

GoetzFIELDS iPDR - TDS MAG Requirements 13 TDS-07 MAG Interface – CDI –TDS shall provide an electrical interface to the MAG Electronics capable of: [a] setting control registers [b] receiving MAG Science and Engineering data [c] provide MAG AC heater synchronization

GoetzFIELDS iPDR - TDS AEB Requirements TDS-08 Antenna Electronics Board Interface (AEB) –TDS shall provide an electrical interface to the Antenna Electronics Board capable of: [a] setting Biasing D/A converters and relays [b] reading back the biasing voltages [c] provide DC-DC converter synchronization 14

GoetzFIELDS iPDR - TDS LNPS Requirements TDS-09 Low Noise Power Supply Interface (LNPS) –TDS shall provide an electrical interface to the Low Noise Power Supply capable of [a] setting control registers for Power Control and Housekeeping Channel [b] receiving an analog housekeeping signal [c] provide DC-DC synchronization 15

GoetzFIELDS iPDR - TDS TDS Requirements TDS-10 Time Domain Sampler Control –TDS shall provide electrical interfaces to the Time Domain Sampler data acquisition system capable of: [a] setting TDS instrument modes [b] receiving TDS instrument data TDS-11 TDS Memory Management –TDS shall include memory such that: [a] is capable of storing ~20 TDS snapshot events [b] allows best available event to be sent to telemetry TDS-12 TDS Instrument Calibration –TDS analog science and analog housekeeping conversion coefficients are determined and provided prior to S/C Integration to include gain, phase and timing 16

GoetzFIELDS iPDR - TDS Science Requirements TDS-13 E Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the low frequency component of E-Field signals TDS-14 E Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the AC or plasma frequency (ranging to ~1MHz) component of E-Field signals." TDS-15 B Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the AC or plasma frequency (ranging to ~1MHz) component of B-Field signals (single axis)." TDS-16 Instrument Calibration –TDS shall provide calibration parameters and algorithms so as to allow conversion from telemetry units to physical units (gain and offset per channel) prior to S/C Integration. 17

GoetzFIELDS iPDR - TDS TDS Block Diagram 18

GoetzFIELDS iPDR - TDS New - TDS FPGA Block 19

GoetzFIELDS iPDR - TDS FIELDS block diagram 20

GoetzFIELDS iPDR - TDS TDS BB2 21

GoetzFIELDS iPDR - TDS TDS – Single Board Data Acquisition System Centers on RTAX4000 FPGA daughter board –Holds all logic, interfaces and LEON 3 processor instantiation TDS event data gathered by 16-bit ADCs at ~2MSa/s –Multiplexed 16-bit data bus Simultaneous acquisition of SWEAP particle counts TDS event data stored directly into dedicated event memory –16MB event SRAM – 8 parts – 512k by 32bits –Circular buffers Processor support –8-bit data bus Local SRAM w/ ECC Local boot PROM (some in FPGA?) Local program EEPROM S/C serial interfaces CDI interfaces to DCB, MAG, SWEAP Device interfaces – AEB, LNPS Mezzanine interface –Diagnostic UARTs 22

GoetzFIELDS iPDR - TDS Configuration in Flight 23

GoetzFIELDS iPDR - TDS Test Configuration at UMN 24

GoetzFIELDS iPDR - TDS Resources TDS mass CBE is 435g (not counting structure) TDS power CBE is 2.17W secondary TDS bit-rate to DCB (flash) is ~10,000 b/s 25

GoetzFIELDS iPDR - TDS Issues TDS design is well advanced –Based on earlier STEREO implementation –More than usual at this point (PDR) Selected ADC is great – but plastic –A cousin was used on STEREO –Putative parts have been obtained (x100) –Lead has been added –DPA has been completed (x5) well –Radiation and beam testing next –Up-screening after that –Backup solutions could be painful in performance and power –Astrium/ESA testing suggests we’ll be ok (only SEU/SEFI sensitive) Overall power –We’re only now getting to good power estimates LVDS protection solution is still open for S/C communications 26

GoetzFIELDS iPDR - TDS Next Continue development work with BB2 –FPGA –FSW –Spacecraft Emulator –FIGs for DCB, MAG and SWEAP –Ground software Modify existing schematic for ETU Layout ETU 27

GoetzFIELDS iPDR - TDS SPP/FIELDS Time Domain Sampler FPGA Preliminary Design Review Keith Goetz University of Minnesota 28

GoetzFIELDS iPDR - TDS TDS FPGA TDS is based on STEREO design –3 STEREO FPGAs and 1 VLSI µP move into one FPGA for SPP TDS is a combination of analog electronics, digital electronics, VHDL firmware and flight software Added System-6 pieces fit in well –Low impact TDS FPGA is central RTAX4000 is the FPGA of choice RTAX4000SL-1 CCGA-1272 –Maybe more than we need in gates but has lots of useable pins CQ352 does not have enough user pins –FIELDS FPGA daughter board makes this a common part/design solution Developed at UCB Used in DCB, TDS and DFB Risk reducer 29

GoetzFIELDS iPDR - TDS TDS FPGA Block 30

GoetzFIELDS iPDR - TDS TDS Data Acquisition/Control Gather time series data –Access ADCs –Front end processing Accumulate SWEAP counts and sync Down sampling e-time series –Send buffered data stream to TDS memory controller Never skipping a beat Generate sampling clock Select muxes 31

GoetzFIELDS iPDR - TDS TDS statistics Peaks and maxes Triggering Langmuir wave statistics Dust analysis High heritage 32

GoetzFIELDS iPDR - TDS TDS Memory Control Accept data steam Accept triggers Control circular buffers –Large dedicated 32-bit memory path –Large dedicated event memory (16MB) Interleave memory access from CPU 33

GoetzFIELDS iPDR - TDS TDS FFT Controller Optional Allows frequency analysis –Redundancy –Enhances dynamic range of new all-digital TNR Large signal spectra Could be done in hardware or software 34

GoetzFIELDS iPDR - TDS HK ADC Controller New Allow FSW access to external ADC/MUX –Analog HK –Analog Science 35

GoetzFIELDS iPDR - TDS S/C TM/TC Interface New UARTS to/from S/C –A/B –S/C Time, Status and Sharing –S/C commands –S/C telemetry HK MAGi –Provides one real-time clock –Common VHDL and FSW with DCB 36

GoetzFIELDS iPDR - TDS Clocks Receive internal clock (from on-board oscillator) Receive external clock (from DCB) Fail-over and back –Slave to DCB when possible Generate clocks for internal/external use –MAGi CDI (4.8MHZ) and heater (300kHz) –SWEAP CDI (4.8MHz) and high-rate clock (19.2MHz) –AEB2 conversion clock (300kHz) –LNPS2 conversion clock (600kHz) –ADC clocking Maintain real-time clock from S/C Maintain real-time clock from DCB 37

GoetzFIELDS iPDR - TDS Watchdog Handles resets Internal watchdog timer –Touched by FSW –If not touched delivers a reboot –Generally, the watchdog time is long 220s in the past – shorter here 38

GoetzFIELDS iPDR - TDS DCB CDI Standard CDI slave interface 4.8MHz Also includes high rate clock (38.4MHz) DCB sends TDS time and commands TDS sends DCB fully formed/compressed TDS CCSDS data packets –~10kbps Common VHDL and FSW with DCB 39

GoetzFIELDS iPDR - TDS MAG CDI New Standard CDI master interface 4.8MHz Also includes power supply chopping frequency (300kHz) TDS sends MAG time and commands MAG sends TDS data chunks – one per cycle Common VHDL and FSW with DCB 40

GoetzFIELDS iPDR - TDS SWEAP CDI New Standard CDI master interface –LVDS 4.8MHz Also includes high rate clock (19.2MHz) TDS sends SWEAP time and commands –CBS –MAG vector –Once per cycle SWEAP sends contributions to CBS 41

GoetzFIELDS iPDR - TDS AEB Interface New Parallel and serial interface lines Controls Antenna Electronics Board parameters –Current and voltage biasing Retrieves AEB HK –Controlling AEB MUX Also includes power supply chopping frequency (300kHz) Common VHDL and FSW with DCB 42

GoetzFIELDS iPDR - TDS LNPS Interface New Parallel interface lines Controls MAG power Retrieves LNPS2 HK –Controlling LNPS MUX Also includes power supply chopping frequency (600kHz) Common VHDL and FSW with DCB 43

GoetzFIELDS iPDR - TDS Test UARTS Console –OOB commanding Log –OOB event stream GSE –OOB binary/packet data stream Debug Line drivers on GSE (mezz board) 44

GoetzFIELDS iPDR - TDS Test points Board serial number Blinking light –Software controlled Test input ports Test output ports I/O to EM connector to allow timing/triggering tests 45

GoetzFIELDS iPDR - TDS Processor LEON 3 IP –Free – open source –SPARC V8 –LEON 3 FT planned for flight –STEREO used an earlier version – SPARC V7 IP –Gaisler GRLIB LEON AHB/APB infrastructure GDB GRMON –UARTs 46

GoetzFIELDS iPDR - TDS Processor Support Interrupts DMA Handler Processor RAM –Internal and external Processor ROM/PROM –Internal and external –Internal boot PROM? Processor EEPROM 47

GoetzFIELDS iPDR - TDS Mezzanine Board GSE only RS-232 drivers Reset button Blinking light Logic Analyzer interfaces PROM/EPROM/EEPROM sockets –PROM emulator interface 48

GoetzFIELDS iPDR - TDS RTAX4000 Planned Resource Useage 49 ResourceUsedAvailablePercent Used R-cell15,78320,16078% C-cell31,56740,32078% RAM Block % I/O (D’board)273~350~78% I/O (FPGA) %

GoetzFIELDS iPDR - TDS Peer Review Actions 50 No.Detailed CommentResponse 1 Ceramic caps 0.1uF can be 0805 size, 0.01 can be 0603, all available from Presidio M123 line, 50V Ok 2Use ECC on FPGA internal SRAM bits when they hold commands and control valuesOk 3 Watchdog timer of 220 seconds is long. Consider if this could cause problems with spacecraft control. Could shorter timer work? Ok 4 Verify that you can get a FLASH FPGA version of the full fault protected version of LEON to reduce the risk of surprises when you program the first fuse-based FPGA. TBD 5 Talk to Analog Devices about the fabrication process of the AD7621 to clarify if the part is expected to be insensitive to radiation. Expedite a radiation test to reduce risk. Done 6Show FPGA resource utilizationOk 7Add clock switching algorithm to FIELDS-SWEAP ICD.No 8 Verify the system for switching between clock sources (forward and back) does not violate any timing requirements (runt pulses, etc. Ok 9Consider having common parts for SRAM to share resources / knowledgeOk 10Ask APL for new S/C interface temperatures?

GoetzFIELDS iPDR - TDS Issues ADC acquisition timing –Analysis of ADC read suggestions in AD data-sheet suggests that reading the digital values from multiplexed bus is best constrained to a defined part of the acquisition cycle –Testing will determine the actual requirement and margin –Alternative implementations exist Move the multiplexed acquisition to a faster clock Move to a non-multiplexed ADC data bus –Requires a change from BB2 implementation –Uses extra pins Use as is 51

GoetzFIELDS iPDR - TDS Conclusion No serious issues Experienced team with heritage starting point –Some shared VHDL with UCB Preliminary TDS hardware/firmware design meets or exceeds requirements TDS hardware/FPGA is ready to move into ETU development 52

GoetzFIELDS iPDR - TDS 53 Backups

GoetzFIELDS iPDR - TDS TDS Level 4 - part 1 54

GoetzFIELDS iPDR - TDS TDS Level 4 - part 2 55

GoetzFIELDS iPDR - TDS FPGA statistics 56

GoetzFIELDS iPDR - TDS Slow multiplexed ADC read 57

GoetzFIELDS iPDR - TDS Faster ADC read clock 58

GoetzFIELDS iPDR - TDS Non-multiplexed ADCs 59