Mentor v8.6_4 User Manual
FastScan and FlexTest Reference Manual, V8.6_4
2-76
Add LFSRs
Command Dictionary
Add LFSRs
Tools Supported: FastScan
Scope: Setup mode
Usage
ADD LFsrs lfsr_name {Prpg | Misr} length seed [-Both | -Serial | -Parallel]
[-Out | -In]
Description
Adds Linear Feedback Shift Registers (LFSRs) for use as Pseudo-Random Pattern
Generators (PRPGs) or Multiple Input Signature Registers (MISRs).
Generators (PRPGs) or Multiple Input Signature Registers (MISRs).
The Add LFSRs command defines LFSRs, which FastScan uses as PRPGs, to
create pseudo-random values for the Built-In Self Test (BIST) patterns or as
MISRs to compact responses.
create pseudo-random values for the Built-In Self Test (BIST) patterns or as
MISRs to compact responses.
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. You can
change the default setting of the shift_type and tap_type switches by using the
Setup LFSRs command.
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. You can
change the default setting of the shift_type and tap_type switches by using the
Setup LFSRs command.
You use this command primarily for simulating Built-In Self Test (BIST)
circuitry.
circuitry.
Arguments
•
lfsr_name
A required string that specifies the name that you want to assign to the LFSR.
•
Prpg
A literal that indicates the LFSR functions as a PRPG.
•
Misr
A literal that indicates the LFSR functions as a MISR.
•
length
A required integer, greater than 1, specifying the number of bits in the LFSR.