ACIS Software Traceability

#	Reference	Requirement Description [CEI Rev 06]	Test Meth	Team	Test Objectives	References to SRS Rev B
	CEI 3.1.3	Science Modes
	CEI 3.1.3.1	CCD Readout Modes
1	CEI 3.1.3.1-1	Simultaneous reading of a minimum of 6 data streams from spectral or imaging CCDs	D5	QA	Verify that all (6 imaging & 6 spectroscopy) CCD's are supplying data in timed exposure RAW mode.	¤ 3.2.2.3.19 Table 16 Table 17
			D5	QA	Verify that each science run is uniquely identified.	¤ 3.2.1.3.12
			D5	QA	Verify that the number of exposures is correct.	¤ 3.2.1.3.12
2	CEI 3.1.3.1-2	"Each channel shall collect data from CCDs at max rate 166,666 12 bit words / sec"	T7	HW	Design tests to verify that the CCDs can maintain the commanded data rate. Verify that the pixels are being copied to the FEP image memories, that overclocks are being extracted and stored, and that vertical retrace interrupts are being sent to the FEPs.	TBD
	CEI 3.1.3.1 a)	Timed Exposure Mode
3	CEI 3.1.3.1 a)-1	Be able to command exposure time between 0.1 and 10 sec	R8	SW	Inspect Detailed Design Specification to check that the times have been implemented.	¤ 3.2.2.3.1 , Table 11
			D5	QA	Verify that command times of 0.1, 0.2, 5.0, 9.9 and 10.0 seconds are included in tests. Inspect ACIS time tags in their output streams.	¤ 3.2.2.3.1
4	CEI 3.1.3.1 a)-2	Image to Framestore operation take -- 60 msec	T7	HW	This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
5	CEI 3.1.3.1 a)-3.i	Framestore read operation < 6.5 sec	T7	HW	This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
6	CEI 3.1.3.1 a)-3.ii	Be able to read less than a full frame (sub frame)	R8	SW	Inspect the Detailed Design Specification to verify that this mode has been implemented.	¤ 3.2.2.3.1 , Table 11
			D5	QA	Prepare tests of raw-mode and event-mode timed- exposure sub-frame readout and verify that the frame intervals are correct and that the reported coordinates (event-mode only) are within the sub-frame limits.	¤ 3.2.2.3.1 , Table 11
7	CEI 3.1.3.1 a)-3.iii	Sub frame shall be rectangular	S1	QA	Refer to CEI 3.1.3.1 a)-3.ii	N/A
8	CEI 3.1.3.1 a)-3.iv	"Sub frame read out normal rate, skipped pixels at faster rate"	T7	HW	Inspect output from sub-frame readout tests to see whether pixel skipping has resulted in faster readout times.	¤ 3.2.2.3.1 , Table 11
	CEI 3.1.3.1 b)	Continuous Readout Mode
9	CEI 3.1.3.1 b)-1-i	Be able to read from a maximum of 2 CCDs	D5	QA	Develop 2 raw continuous-clocking mode tests, one using 2 imaging CCDs the other using 2 spectros copy CCDs. (See CEI 3.1.3.1 b)-1-ii) . Examine the resulting telemetry packets for the presence of events from both CCDs.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.17 , Table 30
10	CEI 3.1.3.1 b)-1-ii	Be able to read from a max of 2 CCDs within 6.2 msecs	D5	QA	Use the results of the CEI 3.1.3.1 b)-1-i tests: inspect the output time tags to validate the readout time.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.17 , Table 30
11	CEI 3.1.3.1 b)-2	Be able to sum a commandable number of lines prior to readout	D5	SW	Prepare and execute continuous mode tests with a varying number of on-CCD summed lines.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.17 , Table 30
	CEI 3.1.3.1 c)	Diagnostic Checkout Mode
12	CEI 3.1.3.1 c)-1	Be able to reverse clock each CCD's serial regis ter	D5	HW	Prepare and execute raw timed-exposure and contin uously clocked tests, selecting the "diagnostic" out put register clocking mode. Compare the reported overclock averages against the raw pixel averages.	¤ 3.2.5.3.2
	CEI 3.1.3.2	Data Processing Modes
	CEI 3.1.3.2 a)	Event Mode
13	CEI 3.1.3.2 a)-a-1-i	Identify candidate X-ray events	V4	QA	Refer to CEI 3.1.3.2 a)-a-1-iii	N/A
14	CEI 3.1.3.2 a)-a-1-ii	Remove detector bias & dark current artifacts	A2	SW	"CCD Bias Level Determination Algorithms" , Somigliana and Ford, MIT ACIS, Release 2, May 30, 1995. Verify efficiency and accuracy of bias calibration using "image loader" and selected test images (from CD-R set). See reference .	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.24 , Table 25
				QA	Use an Fe 55 source with full-frame illumination at a range of fluxes. Compare the results with data col lected by the high-speed tap component of EGSE.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.24 , Table 25
15	CEI 3.1.3.2 a)-a-1-iii	"Extract event location, time, and energy"	D5	SW	Verify pixel location, time, and energy in timed- exposure faint event mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 20
			D5	QA	Use an Fe 55 source with full-frame illumination at a range of fluxes. Compare the results with data col lected by the high-speed tap component of EGSE.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 20
16	CEI 3.1.3.2 a)-a-1-iii	Format extracted information for telemetry	I3	SW	Verify reported events in timed-exposure faint event mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 20
17	CEI 3.1.3.2 a)-a-2	Processing of data will not degrade extracted information	D5	SW	Verify reported events in timed-exposure faint event mode and in graded mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 20 ¤ 3.2.2.3.23 , Table 24
	CEI 3.1.3.2 a)-a-3	Determination of candidate event centers
18	CEI 3.1.3.2 a)-a-3-i	Pixel event thresholds shall be commandable	D5	SW	Verify effect of varying event thresholds in timed- exposure faint event mode using "image loader" & test images (from CD-R).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 20
19	CEI 3.1.3.2 a)-a-3-ii	Pixels with bias correction amplitudes exceeding event threshold...	A2	SW	Verify correct threshold logic in timed-exposure faint bias mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
20	CEI 3.1.3.2 a)-a-3-iii	... and are local maxima relative to 8 nearest neighboring pixels	D5	SW	Verify correct local maxima logic in timed-exposure faint bias mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
21	CEI 3.1.3.2 a)-b	Detector bias levels accounted for in bias and dark current removal	T7	SW	Verify correct bias computation and its later use in timed-exposure faint bias mode during SW integra tion tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.24 , Table 25
	CEI 3.1.3.2 a)-c-1	Telemetry consist of 2 sub-modes
	CEI 3.1.3.2 a)-c-2	Faint sub-mode
22	CEI 3.1.3.2 a)-c-2	Transmits all pixel information including loca tion and 9 amplitudes	D5	SW	Verify that 9 pixel values and their locations are being accurately reported, using "image loader" & test images (from CD-R).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
23	CEI 3.1.3.2 a)-c-5	All candidate events shall be telemetered	D5	SW	Verify that all "good" events are being reported in timed-exposure faint bias mode, using "image loader" & test images (from CD-R).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
			D5	QA	Use calibration software within the EGSE to verify that "good" events are being reported.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
	CEI 3.1.3.2 a)-c-3	Bright sub-mode
24	CEI 3.1.3.2 a)-c-3-i	Transmits pixel location and amplitudes at lower resolution	D5	SW	Compare "faint" and "bright" modes, using "image loader" & test images (from CD-R). Verify that the same events are reported when bright-mode grading is turned off.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.23 , Table 24
25	CEI 3.1.3.2 a)-c-4	Loss of spatial distribution and amplitude events is acceptable	A2	SW	Compare tests of "faint" and "bright" modes, using "image loader" & test images (from CD-R). Verify that the "bright" mode amplitudes are derived according to the algorithms in reference [1].	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.23 , Table 24
26	CEI 3.1.3.2 a)-c-6	Grades shall be assigned to candidate events	D5	SW	Compare tests of "faint" and "bright" modes, using "image loader" & test images (from CD-R). Request various bright-mode grades and split threshold amplitudes and verify that the expected events are reported.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.23 , Table 24
27	CEI 3.1.3.2 a)-c-7	Grade shall be a function of amplitude and spa tial distribution	S1	SW	Refer to CEI 3.1.3.2 a)-c-6	N/A
28	CEI 3.1.3.2 a)-c-8	Grade shall distinguish between valid and back ground X-ray events	R8	SW	Compare tests of "faint" and "bright" modes, using "image loader" & test images (from CD-R). Check that specific "background event" pixel patterns are removed by particular BEP grades.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.23 , Table 24
29	CEI 3.1.3.2 a)-c-9	Be able to select events on basis of grade	D5	SW	Compare tests of "faint" and "bright" modes, using "image loader" & test images (from CD-R). Verify that width and intensity of particular spectral lines, e.g. O K , Mn K , are affected by choice of grade.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22 ¤ 3.2.2.3.23 , Table 24
30	CEI 3.1.3.2 a)-c-10-i	Grade selection criteria shall be adjustable	D5	SW	Design a test to verify that grades can be selected a both ends of the specified range.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.23 , Table 24
31	CEI 3.1.3.2 a)-c-10-ii	Possible to include all grade events in telemetry	I	SW	This is the same test as CEI 3.1.3.2 a)-c-3-i	N/A
	CEI 3.1.3.2 a)-d	Event timing
32	CEI 3.1.3.2 a)-d-i	Accurate to within 1 AXAF-I clock pulse	T7	HW	This is primarily a hardware calibration issue the stability of the DEA-start and FEP-exposure latches must be tested. These can be verified by comparing latch times for various DEA settings in parameter blocks.	¤ 3.2.1.3.9 ¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 21
33	CEI 3.1.3.2 a)-d-ii	Relatable to AXAF I clock	D5	SW	This is a design concern, not a validation issue. The relation required by the CEI Specification results from the MHz clock latches.	¤ 3.2.1.3.9 ¤ 3.1.4.6 , Figure 14 ¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.21 , Table 21
	CEI 3.1.3.2 a)-e	Capable of continuous operation with events described as follows:
34	CEI 3.1.3.2 a)-e.i)	Contains -- 1000 pixels < threshold/sec/CCD data stream	T7	SW	Prepare tests in graded event mode that determine the behavior of BEP and more than one FEP when the simulated event rate exceeds 1000 pixels/sec/ FEP.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.11 ¤ 3.2.2.3.23 , Table 24
			T7	QA	Verify this behavior when real CCDs are used in place of the "image loader" .	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.11 ¤ 3.2.2.3.23 , Table 24
35	CEI 3.1.3.2 a)-e.ii)	Total valid X-ray event rate in all 6 CCD data streams of -- 750 events/sec	D5	SW	Use the same test configuration as CEI 3.1.3.2 a)-e.i) and verify that at least 750 events are reported.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.11 ¤ 3.2.2.3.23 , Table 24
			T7	QA	Verify this behavior when real CCDs are used in place of the "image loader" .	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.11 ¤ 3.2.2.3.23 , Table 24
	CEI 3.1.3.2 b)	Timing Mode
	CEI 3.1.3.2 b)-1	Mode used to process data in continuous read out mode
36	CEI 3.1.3.2 b)-2	Amplitude and position info compressed to fit telemetry limits	D5	SW	During continuous readout tests, verify that pixel values and locations are accurately represented in the output stream.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.18 , Table 32
37	CEI 3.1.3.2 b)-3	Data to be time-stamped at least every major frame	I3	QA	Inspect output from a continuous readout test, and verify that sufficient frame latch tags are being reported, i.e. >= one per 32 seconds.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.18 , Table 32
	CEI 3.1.3.2 c)	Bright Source Imaging Mode
38	CEI 3.1.3.2 c)-1	"Loss of temporal, spatial, or spectral resolution employed to fit telemetry rates"	D5	SW	During the CEI 3.1.3.2 a)-e.i) and ii) tests, verify that, if a FEP is unable to keep up with the input data rate, entire frames are skipped by all FEPs.	¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.18 , Table 32
39	CEI 3.1.3.2 c)-2	Processing shall terminate if output data rate exceeds 24 kbps	S1	SW	Refer to CEI 3.1.3.2 c)-1.	N/A
40	CEI 3.1.3.2 c)-3	Processing shall not resume until buffer overflow is eliminated	S1	SW	Refer to CEI 3.1.3.2 c)-1.	N/A
41	CEI 3.1.3.2 c)-4	Buffer size and overflow actions TBD	TBD	SW	Verify during CEI 3.1.3.2 a)-e.i) and CEI 3.1.3.2 a)- e.i) testing that FEP and BEP buffer sizes ( TBD until HW CDR) are adequate to meet CEI requirements.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.11 ¤ 3.2.2.3.23 , Table 24
	CEI 3.1.3.2 d)	Bright Source Spectroscopy Mode
42	CEI 3.1.3.2 d)-1	Provide specialized data compression for TGS observations	A2	SW	Verify two-exposure-time operation in timed-expo sure faint event mode during SW integration tests, using "image loader" and test images (from CD-R set).	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
43	CEI 3.1.3.2 d)-2	Compression shall preserve X-ray intensity as a function of position	N/A	N/A	Since the compression is in the time domain, and is non-destructive, this requirement is automatically met.	N/A
	CEI 3.1.3.2 e)	Calibration and Diagnostic Modes
44	CEI 3.1.3.2 e)-1	All calibration modes shall function when ACIS is at focus or next in line for focus	D5	SW	Verify that bias maps can be computed, and raw his togram mode executed in next-in-line mode (500 baud telemetry).	¤ 3.2.2.3.20 , Table 18 ¤ 3.2.2.3.24 , Table 25
45	CEI 3.1.3.2 e)-2	Full telemetry will be utilized	D5	SW	Verify that ACIS telemetry packets use optimal bit- packing.	¤ 3.2.1.3.10
			D5	SW	Verify that bias maps and raw pixels are compressed efficiently (see reference [1]).	¤ 3.2.2.3.19 , Table 20 ¤ 3.2.2.3.24 , Table 25 ¤ 3.2.3.3.17 , Table 30
			D5	QA	During all tests, tally the percentage of telemetry that is unused, i.e. contains inter-packet pad bytes.
46	CEI 3.1.3.2 e)-2-i	"Mode must provide information on system per formance, noise, CCD charge"	D5	SW	Verify that the calibration modes accurately report pixel and overclock values (raw mode) and their sta tistics (histogram mode) from test images (from CD- R via loader).	¤ 3.2.2.3.19 , Table 20 ¤ 3.2.2.3.20 , Table 18
47	CEI 3.1.3.2 e)-2-ii	"transfer efficiency, CCD Dark current, spectral resolution,"	T7	SW	Analyze test images using the "image loader" & CD- R files. Verify that the resulting data packets are ade quate for science calibration, e.g. that the measured bias values and width of particular spectral lines is the same as that derived from the same data frames by the ACIS calibration team.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
48	CEI 3.1.3.2 e)-2-iii	"energy-to-pulse height gain, CCD quantum effi ciency, background event rate"	T7	SW	Analyze test images using the "image loader" & CD- R files. Verify that the resulting data packets are ade quate for science calibration, e.g. that the energy, QE, event rate, etc., of particular spectral lines is the same as that derived from the same data frames by the ACIS calibration team.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.22 , Table 22
49	CEI 3.1.3.2 e)-3	Mode shall be capable of full frame transmission	D5	SW	Conduct tests of raw mode timed-exposure and con tinuously clocked telemetry. Verify that all pixels are being reported.	¤ 3.2.2.3.1 , Table 11 ¤ 3.2.2.3.19 , Table 20 ¤ 3.2.3.3.1 , Table 26 ¤ 3.2.3.3.17 , Table 30
50	CEI 3.3.10	Software will be compatible to AXAF-I IAW Science Instrument ICD	S1	-	See below.	N/A
	CEI 3.7.5	Flight Software Subsystem
	CEI 3.7.5.1	General
51	CEI 3.7.5.1-1-i	"SW will conform to CQ-5330.1, MM-8075.1 and NMI-2410.6"	R8	QA	This is ensured by following the directives in the ACIS Software Quality Assurance Plan.	¤ 1.2
52	CEI 3.7.5.1-1-ii	Implement SI control and redundancy manage ment	D5	QA	This is not subject to verification by flight software, which is unaware of redundancy state. It will be tested by ACIS EGSE during hardware integration.	N/A
53	CEI 3.7.5.1-2	Provide for on-orbit changes and memory dump capability	D5	SW	Verify the action of the code patch and memory load/ dump commands.	¤ 3.2.8 (memory) ¤ 3.2.11 (patch)
			V4	QA	Verified that all memories can be examined and mod ified at their address limits.	¤ 3.2.8 (memory) ¤ 3.2.11 (patch)
54	CEI 3.7.5.1-3-i	Implement CCD readout modes	D5	SW/ QA	Conduct tests of all science operating modes.	¤ 3.2.2 (timed) ¤ 3.2.3 (continuous)
55	CEI 3.7.5.1-3-ii	Implement modes of section 3.1.3	S1	QA	Ensure that tests have been performed in all imple mented science modes.	¤ 3.2.2 (timed) ¤ 3.2.3 (continuous)
	CEI 3.7.5.3	Functions
	CEI 3.7.5.3-a	Executive
56	CEI 3.7.5.3-a(1)	Interrupt Service	R8	QA	Review SI code to ensure that interrupts are handled.	N/A
57	CEI 3.7.5.3-a(2)	Power-on/initialization	D5	HW	This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
58	CEI 3.7.5.3-a(3)	Scheduler	R8	QA	Review SI code to verify the presence of a scheduler.	N/A
59	CEI 3.7.5.3-a(4)	Mode control	N/A	N/A	Redundant requirement. Refer to CEI 3.1.3.	N/A
60	CEI 3.7.5.3-a(5)	Service routine	R8	QA	Verify ACIS memory examination and modification capabilities.	¤ 3.2.8
61	CEI 3.7.5.3-a(6)	Utility	D5	QA	Verify software housekeeping commands and telem etry.	¤ 3.2.9
	CEI 3.7.5.3-b	Communication
62	CEI 3.7.5.3-b(1)	Command Processing	R8	QA	Redundant requirement. Refer to TRW 3.6.1.1.1.2.	N/A
63	CEI 3.7.5.3-b(2)	Telemetry control processing	R8	QA	Redundant requirement. Refer to CEI 3.1.3.	N/A
	CEI 3.7.5.3-c	Redundancy Management
64	CEI 3.7.5.3-c(1)	Fault detection and isolation	TBD	QA	Refer to SW FMEA 36-01104.	N/A
65	CEI 3.7.5.3-c(2)	Periodic Self Test	D5	QA	Needs to be designed.	TBD
66	CEI 3.7.5.3-c(3)	Hardware reconfiguration	R8	QA	This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
	CEI 3.7.5.4	Fault Management
67	CEI 3.7.5.4-1-i	Capable to detect and isolate faults	TBD	QA	Refer to SW FMEA 36-01104.	N/A
68	CEI 3.7.5.4-1-ii	Reconfigure redundant units	D5	GSE	This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
69	CEI 3.7.5.4-1-iii	Report status	D5	SW	Verify that reboot status is accurately reported in test telemetry.	¤ 3.2.9.3.5 , Table 64
				QA	Verify that DEA software housekeeping is accurately reported.	¤ 3.2.10.3.1 , Table 66
70	CEI 3.7.5.4-1-iv	Provide sufficient data to OTS to verify instru ment operation	TBD		This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
71	CEI 3.7.5.4-1-v	Provide sufficient data to ground controller in critical situations	TBD		This is not subject to verification by flight software. It will be tested by ACIS EGSE during hardware integration.	N/A
	CEI 3.7.5.5	Periodic Self Test
72	CEI 3.7.5.5-1	Provide for self test of computational elements	D5	SW	Verify the action of raw frame (in timed-exposure and continuous modes) and histogram commands (timed-exposure mode only).	¤ 3.2.2.3.19 ¤ 3.2.2.3.20 ¤ 3.2.3.3.17
	CEI 3.7.6	Data and Command Subsystem
73	CEI 3.7.6-1	AXAF-I Observatory, SI ICD, TRW, Oct 11 1994. See below. Command formats shall be compatible with AXAF-I to SI ICD	S1	-	See below.	N/A