SECCHI Flight Software

Dennis Wang

wang@ares.nrl.navy.mil

202-404-1401

SECCHI Consortium Meeting July 2001 - RAL

• CPU Utilization• Memory Usage•VxWorks•H/W Interfaces•S/W Reuse and Upgrades•S/W Requirements•Current Activities

RAD 750

• 240 MIPS, 133 MHz clock speed, 33 MHz CPCI Bus speed, PowerPC = 10 W

• 166 MHz version may be available

• Clock speed can be reduced to save power

60 MIPS, 33 MHz clock = 6.1 W

• Sleep modes with rapid wake can also be used to save power

LASCO CPU Utilization

• LASCO used 0.6 MIPS for 15 kbits/s

• LASCO Used 1 MIPS for control of heaters, mechs and housekeeping functions

• LASCO used 0.8 MIPS for Image Processing

CPU Utilization

• Image processing and compression for COR1, COR2, EUVI, HI-1 and HI-2 scales with the ratio of STEREO/LASCO TM

• Guide scope and Space Weather equal to 1 MIP• HI requires additional processing for cosmic ray

scrubbing and summing of images• HI-1 cadence is 222 images/hr• HI-2 cadence is 56 images/hr

CPU Operations

• PCI Memory get/copy 1 pixel/33 MHZ clock

• Add, compare, subtract (2 clocks @ 133MHz)

• Multiply, Divide (20 clocks @ 133 MHz)

• Processor pipeline typically gets >1 operations/clock

HI Image Processing

• Bias subtraction – 1 subtract, 1 get/copy

• 2 Image Cosmic Ray Scrub – 2 compare, 1 get/copy

• 3 Image Cosmic Ray Scrub – 3 compare, 1 get/copy

• Summing – 1 add/sub, 1 get/copy

CPU UtilizationTask MIPS MIPS + 15%

C&DH 2.24 2.58

HK 1 1.15

Guide Scope 1 1.15

Image Processing 3.59 4.13

HI (3 Image CR Scrub)

25.9 29.79

Total 33.7 38.8

Memory Usage

0

20

40

60

80

100

120

140

160

180

200

176 MB

MB

TM BufferEUVICOR 1COR 2HI 2 BuffHI 1 BuffHI 2 SBHI 1 SBVxWorks

Memory Map

• Buffers for each instrument allow rapid image taking for PB and B images for COR 1 and COR 2, EUVI color sequence

• Near independent timeline for each instrument – no sharing of image buffers

• Only CCD readout needs to be managed

• Important for HI-1 and HI-2

Memory and CPU Tradeoffs

• Additional memory is used to increase image cadence for short periods (TM Buffer) or to take and store interesting images (CME detect buffer)

• Additional MIPS used for additional image processing beyond what was done for LASCO e.g. JPEG 2000, MPEG movies, CME detection

VxWorks

• Real-Time multitasking operating system used for SMEX, Triana, SXI and others

• C or C++• Code size for Triana ~800kB, SXI ~ 500kB• SECCHI should be ~1 MB• SXI code heritage for mechanisms and

heaters, housekeeping, LASCO – Image Acquisition and Processing

Triana ?

Hammers Co. has Triana code on PowerPC 750 and will have code on RAD750 by the end of the year

• Familiarity with Triana S/C code and docs

• Infrastructure routines such as VxWorks, EEPROM, watchdog should be 100% applicable

• Other routines may be applicable (messaging, task management)

H/W Interfaces

• MIL-STD 1553 to spacecraft for HK and SC TM – 40-80 kbits/s SCI TM (SWIFT)

• IEEE 1355 High Speed Serial Camera Interface (similar to SWIFT 1355)

• RS-422 to HI/SCIP Mechanism Electronics

• HK board to photodiodes of Guide Telescope

VxWorks and SXI Software

• Fixed priority task scheduling

• Multiple task threads

• Interrupt control and vector setup

• Intertask communications using message queues, signals and semaphores

• SXI uses message queues for intertask communications

SECCHI Upgrades

• Scheduling and timeline, schedule macros

• Multiple SECCHI instruments vs single SXI telescope

• Observing programs

• Image Processing

• Image Compression

S/W Req – Instruments

• Observing programs handle complete observation acquisition

• Normal, dark, cal lamps, EUVI color sequence, polarizer sequence, continuous readout

• HI image acquisition and summing• 2048x2048 pixels @ 1 or 2 (dual port CCD)

Mpixels/s• Observations synced to 1 sec UTC (0.5 sec

requirement/spacecraft)

S/W Req - Command

• S/W Modular design for uplink - 100kB/day

• Bit packed command sequences

• Table driven camera setup and image proc.

• On-board schedule sequences and default observing sequence

• Real-time commanding for diagnostics and I&T

S/W Req – Schedule & Ops

• Independent operation of each telescope’s mechanisms and lamps

• Scheduled camera readout (1 HI camera and 1 SCIP camera simultaneously)

• Schedule items can be modified/deleted• Schedule is based on daily uplink• Schedule is to be repeated if no ground

contact or default sequence

S/W Req – Data Handling

• Image compression lossless (Rice) and lossy (H-compress, SQRT, divide by 2)

• ROI, occulter and F.O.V masks

• Diagnostics (Test, None, Debug, Header)

• Summing and Cosmic Ray Scrub for HI

• Space Weather channel – JPEG

• Data Volume = 3.5 –7 Gbits/day/spacecraft

S/W Req - Spacecraft

• Time Sync Message 1 per sec to 1/256 sec resolution with additional 64 microsec offsets

• Status Bits - Fine pointing, thruster firing, power off warning

• Watchdog• Guide Telescope attitude data for ACS• Dual SSR partitions (overwrite or block when full)

– priority of downlink ?

Software Development Plan

• Software Code Management (SCCS) and problem reporting and tracking software (GNATS or Teamwork) will be used to control the code, documentation and data

• Snapshots of each build• Software Reviews will be used to validate

requirements and design• Software Tests with well defined criteria for

success will verify quality

S/W Schedule

• 5/16/01 S/W, Ops, Data Sys Peer Review

• 6/01/01 Flight Software Req Draft 1

• 7/23/01 Flight Software Req Draft 2

• 1/15/02 Build 1 – low level infrastructure

• 5/31/02 Build 2 – driver level tests

• 7/01/02 MOC-S/C Simulator Tests

Recent Activities

• Software Development and GSE Lab Setup

• Test setup for working with flight and non-flight hardware – commercial RAD750

• 4links Space Wire tests

• Software Requirements Draft 2 release

• Software Development Plan

• Study SXI and Triana flight software

SECCHI Software Lab (NRL)

SECCHI Software Lab (NRL)