Tektronix 071-0590-00 user manual Other Tx Patterns

BERT Primer

D Q1

CLK

output

D Q2 D Q3 D Q4 D Q5 D Q6 D Q7

Figure B-3. Seven-stage PRBS generator (27-1 PRBS) with taps at 6 and 7

The serial patterns generated by the four stage 24-1 PRBS generator (figure B-4 on previous page) is listed below.

Table B-3. 24-1 PRBS pattern for Four Stage PRBS Generator

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

Other Tx Patterns

Other types of digital patterns may be sent by the generator. Some of these are:

∙Mark/Space Density (groups of 1’s and 0s)

∙Custom Pattern entered into the BERT Tx Memory

In some cases, pattern data for error measurement is fed directly to the BERT

Receiver for comparison “in real time” with the received data from the DUT.

The Tektronix GB700 and GB1400 instruments have this capability.

B-6 GB1400 User Manual