Tektronix 071-0590-00 user manual Stressing through pattern generation

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Stressing through pattern generation

One common stress test employs a pseudorandom binary sequence (PRBS) generator to create test data. The PRBS generator is seeded with a nonzero pattern of n bits. Using a shift register with XOR feedback, the PRBS will cycle endlessly through every combination of n-bits (except for the all-zero state), with no repeats until every combination has been generated (see Figure 3 and Table 2 for the 24-1 PRBS).

XOR

A

B

C

D

Figure 3. 24-1 PRBS (pseudorandom binary sequence) generator

Table 2. 24-1 PRBS pattern

Clock	A	B	C	D	C XOR D
1	1	0	0	0	0
2	0	1	0	0	0
3	0	0	1	0	1
4	1	0	0	1	1
5	1	1	0	0	0
6	0	1	1	0	1
7	1	0	1	1	0
8	0	1	0	1	1
9	1	0	1	0	1
10	1	1	0	1	1
11	1	1	1	0	1
12	1	1	1	1	0
13	0	1	1	1	0
14	0	0	1	1	0
15	0	0	0	1	1

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