Specifications

7-4
Softkey Menu Descriptions
Pattern Softkey Menus
Pattern Softkey Menus
Path
or
Description
The softkey enables menus of softkeys allowing the user to select from the
following:
• One of five PRBS patterns - unmodified, or with zero substitution or mark density
modification
• One of four internal RAM-based User patterns
• One of eight disk based User patterns
• Access a powerful editor which enables the user to recall, edit and save any User
pattern
The softkeys are as follows:
,
Enables the user to select one of five pure Pseudo-Random
Binary Sequences, PRBS. The expressions represent the
lengths of the patterns, in bits.
,
Select from one of four modified PRBS which are Pseudo-
Random Binary Sequences with an extra zero added to the
longest run of zeros, and with a run of zeros (Zero
Substitution) being substituted for the normal bits that follow
the longest run of zeros in the pattern.
Enables the user to set the total length of the longest run of
zeros. The longest run can be extended to the pattern length,
minus 1. The bit after the substituted zeros is set to 1. This
key is only enabled when a ZEROSUB pattern is selected.
pattern
MENU
pattern
pattern
pattern
pattern
prbs
2^31-1 PRBS
2^23-1 PRBS
2^15-1 PRBS
2^10-1 PRBS
2^7-1 PRBS
pattern
zero sub
2^13 ZEROSUB
2^11 ZEROSUB
2^10 ZEROSUB
2^7 ZEROSUB
LONGEST RUNZERO