1. Marek Morawski, Hanna Rothkaehl Space Research Centre PAS
ESA EJSM/JGO Radio & Plasma Waves Instrument Digital Processing Unit (architecture and design concept)
Marek Morawski, Hanna Rothkaehl
Space Research Centre PAS

2. DPU Architecture

3. Board Supervisor Unit
Do we need floating point arithmetic processor ?

4. BSU – Main Tasks
The BSU features should cover all functions required for minimum instrument functionality
Internal mode control
Tele command (TC) verification, validation and execution
Switching and commanding of measurements module
Data collection and buffering
Telemetry (TM) packet formatting and sending
Housekeeping data collection

5. Clock Management Unit
The Clock Management Unit is dedicated to provide stable clock source for BSU and SPU modules.

6. Clock and Module Control I/F
Maximum clock frequency up to 100 MHz (Power consumption !!!)
The same reference & transmission clock for all
Multi-Drop LVDS control data transmission common for all modules
Is redundancy needed?

7. Memory Unit Code loader & Exception service (*)
Application software code (*)
Application data structures (*)
Configuration and calibration tables
Software patches
Configuration bit streams of SPU FPGA
Telemetry packet buffer (*)
Correct Always
&
Scrubbing

8. Housekeeping Acquisition
The analogue to digital conversion is based on comparison of measured value to generated Sigma-Delta ADC embedded in BSU FPGA. (RC net outside)
44031RC Precision Epoxy NTC Thermistor
(YSI )
Phobos-Grunt –JAN 2011
RELEC – End of 2011
Reference
Ur = 2.5V
Voltage
Ux = 0 to 5.0V
Temperature
T = -60°C to 100 °C (TBC)

9. Signal Processing Unit
Implementation of RAM configured FPGA (Xilinx)
Part
Main Feature
TID
SEL
[krads(Si)]
MeVcm2/mg
XQR4VFX60
60k logic cells 2 PowerPC ~4Mb RAM
300
100.0
XQR4VSX55
55k logic cells 512 DSP slices
~5.7 Mb RAM
Possibility of reconfiguration during the flight
Algorithm hardware implementation
Wide portfolio of IP modules
TMRTool (triple logic)

10. Data exchange block diagram
In case of „Signal Processing Unit” failure (or switched off) the data stream could be caught by BSU (reduced performance)