Mentor v8.6_4 User Manual

FastScan and FlexTest Reference Manual, V8.6_4

Tools Supported: FastScan and FlexTest

Scope: All modes

SET CLock Restriction ON | OFf | Clock_po

SET CLock Restriction ON | OFf

Specifies whether the ATPG can create patterns with more than one active capture
clock.

The Set Clock Restriction command changes the default behavior of the ATPG
regarding the creation of test patterns that have more than one active clock line.
The invocation default behavior is different depending on whether you are using
FastScan or FlexTest. FastScan defaults to the Clock_po behavior, while FlexTest
defaults to the On behavior.

The Arguments description that follows describe the different behavior of the Set
Clock Restriction command for each tool.

•

A literal that specifies for the ATPG to create only patterns with, at most, a
single active clock.

For FastScan — The ATPG treats equivalent clocks as a single clock,
however, it treats multiple active clocks as a conflict condition and performs an
exhaustive search for conditions necessary to detect the fault with no more
than one active clock. Faults which the ATPG detects at primary outputs (POs)
that connect to clocks must also satisfy this condition. Faults detected at clock
POs that require multiple active clocks for detection, require that you use the