Command Dictionary

Setup LFSRs

 

 

Setup LFSRs

Tools Supported: FastScan

Scope: All modes

Usage

SETup LFsrs {-Both -Serial -Parallel}{-Out -In}

Description

Changes the shift_type and tap_type default setting for the Add LFSRs and Add LFSR Taps commands.

The Setup LFSRs command controls the default setting for the shift_type and tap_type switches. You specify the LFSR’s shift technique by using one of the following shift_type switches: -Both, -Serial, or -Parallel. You specify the placement of the exclusive-OR taps by using one of the following tap_type switches: -Out or -In. When you change one or both of the default settings, all future Add LFSRs and Add LFSR Taps commands use the new default.

You use this command primarily for simulating Built-In Self Test (BIST) circuitry.

Arguments

The following lists the three shift_type switches of which you can choose only one:

-Both— A switch specifying that the LFSR shifts both serially and in parallel. This is the default behavior upon invocation of FastScan.

-Serial— A switch specifying that a serial shift LFSR shifts a number of times equal to the length of the longest scan chain for each scan pattern.

-Parallel— A switch specifying that a parallel shift LFSR shifts once for each scan pattern.

FastScan and FlexTest Reference Manual, V8.6_4

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Image 635
Mentor v8.6_4 manual Setup LFSRs, SETup LFsrs -Both -Serial -Parallel-Out -In