LFSR

Function

A fast counter with pseudo-random outputs.

Configurations

• One2Many - fastest: uses multiple two-input xor gates;

• Many2One - most compact: uses single multiple input xor gate;

• AllowZero - Basic LFSR's never reach a count of all zeros so they have 2**N-1 counts. If AllowZero is set to true additional logic is added to permit a zero count with a full 2**N counts, but this requires additional resources and reduces maximum speed of the counter.

Reference

http://en.wikipedia.org/wiki/LFSR

Name

Description

WIDTH

Width of the output Q port.

Name

Variants

Edge

Rising, Falling

CountEn

UnUsed, Used

Set

Sync, Async

Mode

One2Many, Many2One

AllowZero

False, True

Name

Width

Condition

Description

CountEn

CountEn= Used

SyncSet

Set = Sync

AsySet

Set = Async

Name

Width

Condition

Description

Q

WIDTH