Atec gigaBERT1400, User Manual

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BERT Primer
B-6 GB1400 User Manual
CLK
D Q1 D Q2 D Q3
output
D Q4 D Q5 D Q6 D Q7
Figure B-3. Seven-stage PRBS generator (2
7
-1 PRBS) with taps at 6 and 7
The serial patterns generated by the four stage 2
4
-1 PRBS generator (figure B-4
on previous page) is listed below.
Table B-3. 2
4
-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.