GC2011A Datasheet, PDF (26/50 Pages) Texas Instruments – 3.3V DIGITAL FILTER CHIP

GC2011A 3.3V DIGITAL FILTER CHIP
SLWS129A
3.10 DIAGNOSTICS
The user can use the ramp input and the snapshot memory to perform diagnostics on the chip. The suggested
diagnostic procedure is to configure the chip as it will be used in normal operation, but to select the ramp as the data
input source (see Section 6.1), to set the counter control to 0FFF _HEX (see Section 6.4), and to set the snapshot controls
to capture 128 output samples (see Section 6.7). The snapshot should be triggered on TC with a delay of 4 blocks from
trigger. The delay guarantees that the filter has flushed and settled out before the snapshot is taken. The user can then
read the snapshot from memory and compare it against a known snapshot or save it for future comparison.
Two suggested diagnostic configurations are given below along with the expected snapshot output. These
configurations use all of the coefficient registers and all of the forward and reverse delay storage registers. The
diagnostic procedure is, for each test configuration in table 11:
(1) Load the 11 control registers with the values shown in Table 11.
(2) Load the coefficients h(k) in addresses 128+k for k=0 to 127.
(3) Set the start bit in the snapshot register by writing 0413_HEX to address 10.
(4) Wait, while reading address 10, until the register value is 0463_HEX.
(5) Read addresses 256 through 271 and 384 through 399 and compare them to the expected values in
Table 12.
Table 11: Diagnostic Test Configuration
Parameter
h(k)
A_PATH_REG0
A_PATH_REG1
B_PATH_REG0
B_PATH_REG1
CASCADE
COUNTER
GAIN
OUTPUT
SNAP_REGA
SNAP_REGB
SNAP_REGC
NEW_MODES
Address
k modulo 4 = 0
k modulo 4 = 1
k modulo 4 = 2
k modulo 4 = 3
0
1
2
3
4
5
6
7
8
9
10
12
Test A Test B
EAAA
FFFF
0F0F
0001
C402
0292
D402
0214
1000
0FFF
1035
0041
004E
004F
0403
0000
1555
E000
F0F0
1FFF
E402
0108
E402
02F2
2F00
0FFF
103A
0041
004F
005F
0403
0000
Address
256
257
258
259
260
261
262
263
Test A Test B
C302
C2E2
C2C2
C2A2
C282
C262
C243
C223
A635
A606
A5D7
A5A8
A578
A549
A51A
A4EA
Table 12: Expected Test Results
Address
264
265
266
267
268
269
270
271
Test A Test B
C621
CA1F
CE1E
D21D
D61B
DA1A
DE19
E217
C3D3
C8BD
CDA6
D290
F692
0094
0A97
1499
Address
384
385
386
387
388
389
390
391
Test A
3BC2
3BE2
3C02
3C22
3C42
3C62
3C82
3CA2
Test B
4BAD
4B7E
4B4F
4B1F
4AF0
4AC1
4A91
4A62
Address
392
393
394
395
396
397
398
399
Test A Test B
3CC2
3CE2
3D02
3D22
3D41
3D61
3D81
3DA1
4A33
4A04
49D4
49A5
4976
4947
4917
48E8
Texas Instruments Incorporated
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