Flight Software PDR Presentation

1
Flight Software PDR Presentation
HMI00373

• Jerry Drake
• HMI Software Lead
• jerry.drake_at_lmco.com

2
Agenda Flight Software

• Requirements
• Sources
• Driving requirements
• Heritage - Flight Processor and Software
• Design Description
• Development Environment
• Context Diagram
• Computer Software Configuration Items (CSCIs)
• Start-Up ROM (SUROM) Software
• Architecture
• Flight Software Overview
• Architecture
• Camera Operational Modes
• Sequence Control
• Time Handling
• Fault Management
• Resource Utilization
• Safety and Reliability
• Software Development Status

3
Requirements Sources

• 464-SYS-REQ-0004, Mission Requirements Document,
  Rev. 4.4
• HMI Contract Functional Specification
• SU-HMI-S013, Instrument Performance Document
• 2H00021, HMI Performance Assurance Implementation
  Plan (PAIP)
• ICDs
• 464-HMI-ICD-0002, Spacecraft to HMI ICD
• 464-CDH-ICD-0005, 1553 ICD
• 464-CDH-ICD-0012, High Speed Bus ICD
• 464-GS-ICD-0001, Ground System ICD
• HMI Hardware Functional Specifications, Section
  4.2, Software Interface
• 2H00119, Functional Specification, HEB Power
  Converter Subsystem
• 2H00120, Functional Specification, HEB PCI to
  Local Bus/1553 Interface
• 2H00121, Functional Specification, HEB
  Housekeeping Data Acquisition
• 2H00122, Functional Specification, HEB Image
  Stabilization Subsystem
• 2H00123, Functional Specification, HEB Mechanism
  Heater Controllers
• 2H00124, Functional Specification, HEB CCD Camera
  Interface
• 2H00125, Functional Specification, HEB Data
  Compressor/High Rate Interface
• 2H00126, Functional Specification, HMI Oven
  Controller
• 2H00180, Functional Specification, HEB
  Electronics Box

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Driving Requirements

• Spacecraft Command I/F Provide command
  capability with spacecraft
• APIDs, sampling rates and protocols contained in
  ICDs
• Commands uplink rate from ground 2 kbps
• Maximum command rate to HMI 10 commands/sec
• Maximum command packet size 250 bytes
• CCSDS formatted
• HMI Command APID range 800 - 815
• Function code identifies each command (in CCSDS
  header)
• Command sources
• Spacecraft
• Ground (1553 through spacecraft) 2 kbps
  (effective 1 kbps)
• STOL
• Manual
• Absolute Time Sequence (ATS) 10 commands/sec
• Relative Time Sequence (RTS) 10 commands/sec
• Telemetry Statistics Monitor (TSM)
• Internal to HMI
• Scripts Same as macro

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Driving Requirements (cont.)

• Spacecraft Telemetry I/F Provide telemetry
  capability with spacecraft
• 1553 Telemetry Channels (Transmit SubAddresses,
  TSA)
• Housekeeping TSA 3 - 6 and completion TSA 7
• Event Message TSA 12 - 13 and completion TSA 14
• Image Motion Compensation TSA 15 and completion
  TSA 16
• Diagnostic TSA 17 - 26 and completion TSA 27
• Wraparound TSA 30
• Accept and respond to transmit mode codes 2, 4, 5
  8
• 1553 Rates
• Housekeeping Nominal 2 kbps, reduced 1 kbps,
  emergency 100 bps
• Diagnostic 10 kbps
• 1355 Telemetry (Science)
• Software controls
• Configuration of 1355 connection
• Two High-Speed Bus Channels per interface card
• Two HSB Interface cards in HMI
• Doppler and magnetic images
• Initiation of transfer (load image parameters)
• Place housekeeping data into science stream

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Driving Requirements (cont.)

• Provide control of subsystems (derived
  requirements)
• Mechanisms (quantity in parentheses below)
• Wavelength Tuning Mechanisms (4)
• Polarization Selector Mechanisms (3)
• Shutters (2)
• Calibration/Focus Mechanisms (2)
• Front Door Mechanisms (2)
• Alignment Mechanisms (2)
• Cameras (2)
• Control image transfers and compression (internal
  to HMI, 2)
• Control image transmission (over 1355 to S/C, 2)
• Image Stabilization System (1)
• Oven (2)
• Operational Heaters (max of 8)
• Provide diagnostic telemetry capability
• High-rate mechanism current or Image
  Stabilization data (up to 5 items at 512 Hz
  sampling rate)
• Provide capability to load code on-orbit

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Driving Requirements (cont.)

• Science
• Maintain regular cadence for doppler and vector
  cameras
• Framelist must start at the requested time within
  /- 100 msec absolute time
• Provide capability for table-driven sequence
  control
• Provide time in telemetry to 100 msec accuracy
• Provide the capability to maintain HMI internal
  clock to an accuracy of /- 100 msec absolute

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Flight Processor/Software and Heritage

• RAD6000 Program A, Program B, Program C, Program
  D
• RAM 4 Mbytes
• EEPROM 512 Kbytes
• PROM (SUROM) 64 Kbytes
• Clock rate 20 Mhz
• PCI bus
• Software Heritage
• VxWorks/RAD6000 Program A, Program B, Program C,
  Program D
• SUROM BAE generic, Program A, Program C, Program
  D
• EEPROM Program C, Program D
• GNUZIP Program B, other program
• Mechanisms MDI, TRACE, Program B, Program C,
  Program D, Program F

9
Development Environment

• Languages
• SUROM
• C
• Assembly
• PAS
• Flight
• C/C
• Tools
• SUROM
• C compiler on RS6000 workstation
• Flight
• VxWorks
• GreenHills Multi
• Sunblade Workstation
• Configuration management tool
• Revision Control System (RCS)
• Schedule
• Purchase Sun workstation and software in Nov 2003
• Install and configure Sun worstation in Dec 2003

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Context Diagram
OVN (2)
ISS Sensor
HTR (8)
ISS PZT
FDM (2)
UART (test)
HMI Electronics Box (HEB)
ALM (2)
COP (test)
Processor (Rad6000)
Processor (Rad6000)
S/C 1553 I/F
WTM (4)
PCI/Local Bus Bridge/1553
PCI/Local Bus Bridge/1553
Cmd/HK
Mech/Heater Controller Type 2
Mech/Heater Controller Type 2
PSM (3)
SDO Spacecraft
Mech/Heater Controller Type 1
Mech/Heater Controller Type 1
PZT Driver
Housekeeping Data Acquisition
CFM (2)
Limb Tracker
Spare
S/C High Rate I/F (2)
SH M (2)
Compressor/High Rate Interface
Compressor/High Rate Interface
Science
Camera Interface/Buffer
Camera Interface/Buffer
WTM Wavelength Tuning Mech PSM Polarization
Selector Mech SHM Shutter Mech CFM
Calibration/Focus Mech FDM Front Door Mech ALM
ALignment Mech ISS Image Stabilization
System OVN Oven HTR Heaters
1355
1355
Doppler Camera Electronics Box
Magnetics Camera Electronics Box
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CSCIs

• Start-Up ROM (SUROM) Computer Software
  Configuration Item (CSCI)
• Commands and HK telemetry over 1553 bus
• Contained in PROM on processor card
• Can upload kernel from ground to RAM
• Can load kernel into EEPROM
• Default is to load kernel from EEPROM to RAM,
  decompress and boot
• Flight SoftWare (FSW) CSCI
• Contained in EEPROM on processor card
• Loaded and booted by kernel code
• Consists of
• Kernel code (VxWorks operating system, device
  drivers, basic cmd and tlm on 1553)
• Flight code

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SUROM Code

• SUROM heritage
• BAE generic, Program A, Program C and Program D
• Development approach
• Develop in simulator (Borland Builder C)
• Establish socket connection to use EGSE
• Test on Program A ODP
• Port from Borland to RS6000
• Test 1553 (ODP processor has 1553 chips on board)
• Test on HMI ETU
• Requires Interconnect board PCI/Local Bridge
  Bus/1553 card with minimal capabilities
• Development system for RAD6000 target
• RS6000 workstation
• C compiler, PAS assembler, RS6000 assembler and
  linker
• COP connection to processor board
• Architecture
• Executive
• State
• 1553
• Command Handler

13
Nominal Boot Sequence

• If no commands are received within 30 seconds (5
  seconds in fast-boot mode) of the first 1553
  telemetry packet, the following occurs
• A copy of the self-extracting VxWorks kernel is
• Read from EEPROM to a default RAM location
• Decompressed
• Executed
• Kernel then
• Initializes memory-resident file systems in
• EEPROM
• RAM
• Locates script file /EEPROM/BOOT0001.SCR
• Executes script file /EEPROM/BOOT0001.SCR
• Script /EEPROM/BOOT0001.SCR contains the list of
  object modules to
• Decompress
• Load into RAM
• Link
• Run for auto-booting
• Other script files (BOOT0002.SCR through
  BOOT9999.SCR) can be used for alternate booting
  by an operator

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Flight Software Architecture Diagram
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Camera Operational Modes

• Clear
• Remove charge from CCD (in preparation for
  obtaining new image)
• Integrate
• During integration, the CCDs parallel register
  clocks will be held at appropriate voltage levels
  
• Serial register clocks can be individually
  programmed to be high, low or clocking
• Dither clocking
• Readout
• Full-frame readout of n lines
• Windowed readout of at least two windows
• Dump n lines
• Read x lines
• Dump m lines
• Read y lines, etc.
• Full-frame or windowed readout with n x m pixel
  binning
• Continuous clocking

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Sequence Control

• Modes
• Science (cadence held)
• Doppler cadence 50 seconds or shorter
• Vector cadence 5 minutes or shorter
• Test and calibration (no cadence, free running)
• Table-driven observing sequences
• Timeline table
• Framelist table
• Focus table
• Polarization table
• Wavelength table
• Tuning table
• Exposure table
• Table contents and definitions currently under
  development with science team
• Tables are uploadable and modifiable
• Can be stored in EEPROM or loaded from ground

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Time Handling

• VxWorks system tick (interrupt)
• OBC derived 1.95 msec (512 Hz)
• RAD6000 decrementer 20 msec (fallback source)
• Time at tone
• Internal clock latched into OBC 1553 Time Tag
  Register by 1553 interrupt on receipt of tone
  message
• Software accesses OBC 1553 Time Tag Register over
  PCI bus
• Rate adjustment
• Send OBC 1553 Time Tag Register in housekeeping
  telemetry
• Ground calculates drift and issues command to
  change rate (if so desired)
• Spacecraft time included in every telemetry
  packet
• Observing cadence maintained by
• Starting sequence on nearest system tick to time
  of day modulo cadence in seconds
• The sequence period must be settable in software
• Command
• Contained in sequence table
• Repeating sequence

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Fault Management

• Internal limit checking of
• Motor current and total current
• Heater zone temperatures
• Camera aliveness
• Alignment Leg Mechanism
• Front Door Mechanism
• Autonomous checks of HMI 1553 bus activity over 2
  (TBR) minutes
• Activity level reported in health safety
  telemetry
• Levels below a settable threshold cause internal
  recovery or safing actions

19
Resource Utilization

• PROM (SUROM)
• Available 64 K
• Expected utilization 95
• HMI SUROM contains less functionality (the HMI
  estimate is conservative) than the Program A
  SUROM which fit into the same 64 K PROM
• SUROM is unchangeable once programmed into PROM
  and installed on the processor board
• EEPROM
• Available 512K
• Expected utilization 11 K file system overhead
• 128 K for compressed kernel
• 128 K for compressed FSW
• 245 K available margin
• RAM
• Available 4 Mbytes
• Expected usage 512 Kb FSW
• 512 Kb RAM filesystem
• Up to 3 MB telemetry buffers for diagnostic
  data storage (infrequent)
• CPU Usage
• FSW 30

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Safety and Reliability

• Safety
• HMI flight software cannot cause loss of mission
  or injury or death to humans
• Coding standards will be used (2H00006) to
  increase safety and reliability
• Possible safety items
• Programming EEPROM
• Operating front door mechanism, alignment legs
  and/or heaters
• Fault management will be implemented (see next
  slide)
• Safety issues addressed at all major program
  reviews
• Reliability
• FSW developed incrementally
• FSW tested in simulation and emulation
• FSW will be used for as much hardware testing as
  possible
• Idle task shall detect and report in telemetry
  CPU usage percentage and overrun (if any)
• Exception handling shall capture and report task
  errors
• Internal consistency checks shall be made on cmd
  parameters initial use of global pointer values

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Software Development Status

• Completed Peer Review on October 8, 2003
• Complete Software Requirements Document
• Initial draft submitted with CSR and updated for
  PDR
• Complete hardware board specifications
• Complete
• Command list (draft currently exists)
• Telemetry list (draft being prepared)
• Start detailed design
• SUROM and kernel in progress
• FSW starting
• Develop Software Design Documents
• Establish interface between simulator and EGSE
  (to confirm design approach)
• Risks
• Complexity of camera control interface