Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3166c Report Date: 09-May-96:18:07 Version: ********** Check-in Date: ********** 1.Proposal Title: NSSC-I S/W PAYLOAD SAFING PATCH ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID ENG Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Glenn Foley CODE 512 USA ------------------------------------------------------------------------------------ 7. Abstract This proposal was developed to install the "software payload safing" patch to the HST NSSC-I Baseline 3.12a flight software. This approach requires both realtime and stored command elements. Stored commands will be used to perform the actual patching of memory and realtime actions will activate the sorted command sequences and monitor the progress of the installation. Installation requires modification of 3 distinct regions of memory. The first is a 34 word section to be placed in in bank 4 (numbering from 0) which contains the data referenced by the new code. The 2nd is the code which actually performs the new functionality. It is a 44 word region to be placed in bank 7. The 3rd area is in the existing NSSC-I code which processes the SSM PIT. It is a 14 word region in bank 6 which will link the existing code to the new code. 4 NSSC-I relative time command sequences (RTCSs) are required for the installation: one to memory load each of the 3 above regions and a 4th to return the code to its original config.,disabling disabling the new ability. These will be referred to as the Data Patch RTCS, New Code RTCS, Linkage Patch RTCS, and Unpatch RTCS. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3166c PI: Glenn Foley Proposal Title: NSSC-I S/W PAYLOAD SAFING PATCH ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Glenn Foley GFSC/CODE 512 USA X ------------------------------------------------------------------------------------ 2. Scientific Justification. The Data Patch RTCS consists of a trivial memory load. It has the form: memory load 34 words The New Code Patch RTCS also contains a memory load, but its logic is more complex since it must modify a region of memory that is protected against change by the NSSC-I flight s/w. Before it can be loaded, the RTCS must deactivate the error processing performed by the NSSC-I memory checksum diagnostic and change a constant which delimits the region of memory that can be memory loaded. This is of the form: disable checksum error processing change code start constant memory load 44 words restore code start constant wait 4mins enable checksum error processing The Linkage Patch and the unpatch RTCSs also require deactiva ting the checksum error processing and changing the code start constant, but have another level of complexity: both involve modifying the code of an interrupt handler which executes every .5 secs and cannot be disabled (SSM PIT processing). Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. It must be assured that the interrupt does not occur when the memory load is in progress, thus the elements of the RTCS which perform the load must be coordinated with the expected arrival of the SSM PIT. The linkage patch is of the form: disable checksum error proc. change code start constant wait for NOT start of major frame wait for start of major frame wait for 40 minor frames plus 175 millisecs memory load 14 words restore code start constant wait 4mins enable checksum error proc. The Unpatch RTCS is of the form: disable checksum error proc. change code start constant wait for NOT start of major frame wait for start of major frame wait for 40 minor frames plus 175 millisecs memory load 14 words memory load 44 words restore code start constant wait 4mins enable checksum error proc. In the unpatch RTCS the memory load of 14 workds is done to restore the code in the SSM PIT proc. software used to link to the new code, to its previous baseline 3.12a config. The memory load of 44 words will return the area used for the new code to zero. The order in which the RTCSs are activated is critical. However the timing between steps relative to one another is not: time which elapses between any two steps may be of arbitrary duration time critical are in the NSSC-I RTCSs. The QMONDADDS Table refer to the NSSC-I memory monitor programmable telemetry capability. This Table may be loaded with the addresses of up to 20 locations in NSSC-I memory and the contents of those locations reported in the eng'rng telemetry every 30secs. INSTALLATION STEPS: SETUP 0. s/w dump NSSC-I memory banks 0-11 decimal (12 banks); update Ground Master Image after each dump. 1. initial config: C&DH in normal mode; 4 installation RTCSs loaded in NSSC-I stored command memory and enabled 2. condition QMONADDS table slots 17-20 and look at locations in NSSC-I memory: slot 17 - SSMPIT (1st word of SSM PIT received contains safing bits) slot 18 - QMEMCHEK (indicates whether checksum error proc. enabled) slot 19 - QLIMITS (code start constant) slot 20 - QMEMCKSM (value calc.by checksum proc.) Data Section 3. Condition QMONADDS table slots 1- 16 to look at 1st 16 words of data patch area 4. activate the Data Patch RTCS 5. verify the first 16 words of the data patch area with memory monitors; snap page CDHMEMOC 6. condition QMONADDS table slots 1-16 to look at 2nd 16 words of Data Patch area 7. verify 2nd 16 words with memory monitors; snap page CDHMEMOC 8. condition QMONADDS table slots 1-2 to look at last 2 words of data patch are 9. verify last 2 words via memory monitors; snap page CDHMEMOC New Code Section 10. activate New Code Patch RTCS 11. verify new checksum is octal 715250 w/memory monitors 12. verify New Code Patch complete (MOC page CDH1) Linkage Section 13. acitivate Linkage Patch RTCS 14. verify new checksum is octal 760721 w/memory monitors 15. verify Linkage Patch complete (MOC page CDH1) Cleanup Section 16. s/w dump NSSC-I memory banks 4,6,7 (numbering from 0); print descrepancy report; verify patched areas; update Ground Master Image after each bank is dumped. Procedure to deinstall the patch would be to activate the Unpatch RTCS. The final checksum octal would be 020402, the initial NSSC-I baseline 3.12a value. Page 4 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Estimated Vehicle Resources are given for the sections of the realtime procedure labelled Setup, Data, New Code Linkage and Cleanup. Resources are divided into SSA forward link time, MA engineering return link time, 1M SA science return link time, and the time required before proceeding to next section ("think" time). SSA and 1M SSA science links should be scheduled coincident with or near the start of the associated MA return links. The sole use of the SDF is required for the memory dumps in steps 0-16. All times are in minutes. STEPS SSA LINK MA ENG RETURN 1M SSA SCI. THINK TIME 0 25 25 25 0 1-2 10 15 0 10 3-5 10 15 0 10 6-7 10 15 0 10 8-9 10 15 0 10 10-12 10 15 0 20 13-15 10 15 0 20 CONTINGENCY TIME: 10M FOR SSA, 15M FOR MA ENG. 16 10 10 10 10 No other RTCSs with executive ownership can be activated when the Linkage Patch is active because nesting may perturb the critical time designed into the sequence. It is also desirable to have ALL SIs in HOLD MODE during Linkage Patch activation, to minimize activity in the NSSC-I. NOTE: though such constraints on the NSSC-I are not required for activation of the Data Patch or New Code Patch, having the SI's in hold mode will aid in the potential completion of their installation ahead of schedule, and the NNSC-I will already be in the required configuration for the Linkage Patch. The S/W payload safing patch will be declared operational during the "think time" of the Linkage section if the verifications are successful. "Contingency time" is for the case where a contact is missed or extra time was required to complete a step. If deemed necessary, the Unpatch RTCS will be implemented in the next forward link. ------------------------------------------------------------------------------------ 11. Address Information Name: GLENN FOLEY Category: PI Institution: GFSC/CODE 512 Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3166c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK S/C DATA NONE 1 1M 1 1 CYCLE 0 / 1-2 Comments: REQUIRED TO INSTALL 4 RTCS'S, CONDITION TABLE SLOTS 17-20 TO LOOK AT SSMPIT, QMEMCHECK, QLIMITS AND QMEMCKSM, IN NSSC- 1. SHOULD BE EXECUTED AS EARLY ------------------------------------------------------------------------------------------------------------------------------------ 2 DARK S/C DATA NONE 1 20M 1 1 REQ UPLINK RT ANALYSIS Comments: REQUIRES ALL SI'S IN HOLD,BUT HSP IN SYSON, WFPC IN STANDBY. MODE TO ACTIVATE LINKAGE PATCH (LP) RTCS. ID'S MSSLN001/ EMSSLINK. VERIFY NEW CHECKSUM OCTAL=760721 W/MEM. MONITORS ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3166c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes DATA ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Proposal for ENG ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 0 / 1-2; REQ UPLINK; RT ANALYSIS; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements ------------------------------------------------------------------------------------------------------------------------------------ Target Names ------------------------------------------------------------------------------------------------------------------------------------