Document number
205065
Version
Rev. N
Issue date
2019-02-04
Sirius OBC and TCM User Manual
Page
11
of
174
2. Equipment information
The Sirius OBC and Sirius TCM products are depicted in Figure 3-1 and Figure 3-2.
In addition to the external interfaces, the Sirius products also include both a debugger
interface for downloading and debugging software applications and a JTAG interface for
programming the FPGA during manufacturing.
The FPGA firmware implements a SoC centered around a 32 bit OpenRISC Fault Tolerant
processor [RD1] running at a system frequency of 50 MHz and with the following key
peripherals:
•
Error manager - error handling, tracking and log of e.g. memory error detection.
•
SDRAM controller - 64 MB data + 64 MB EDAC running @100MHz
•
Spacecraft Elapsed Timer (SCET) - including a PPS (Pulse Per Second) time
synchronization interface for accurate time measurement with a resolution of 15 µs
•
SpaceWire - including a three-port SpaceWire router, for communication with
external peripheral units
•
UARTs - RS422 and RS485 line drivers on the board with line driver mode set by
software.
•
GPIOs
•
Watchdog - a fail-safe mechanism to prevent a system lockup
•
System flash - 2 GB of EDAC-protected flash for storing boot images in multiple
copies
•
Pulse command inputs - for reset to a specific software image
•
NVRAM - for storage of metadata and other data that requires a large number of
writes that shall survive loss of power
For the Sirius TCM the following additional peripherals are included in the SoC:
•
CCSDS - communications IP with RS422/LVDS interfaces for radio communication
and an UMBI interface for communication with EGSE
•
Mass memory - 16GB of EDAC-protected NAND flash based, for storage of
mission critical data.
For the Sirius OBC, an Analog interface is included for external analog measurements.
The input power supply provided to the Sirius products shall be b4.5 and +16 VDC.
The power consumption is highly dependent on peripheral loads and ranges from 0.8 W to
2 W.
2.1. System Overview with peripherals
Figure 2-1 depicts a System-on-Chip (SoC) overview including the related peripherals of the
Sirius OBC and Sirius TCM
products. The figure shows what parts that are included for
which products.
