Add Slow Pad

Command Dictionary

 

 

Add Slow Pad

Tools: FastScan

Scope: Atpg mode

Usage

ADD SLow Pad {pin_name [-Cell cell_name]} -All

Description

Sets the specified I/O pin as a slow pad.

While running tests at high speed, as might be used for path delay test patterns, it is not always safe to assume that the loopback path from internal registers, via the I/O pad back to internal registers, can stabilize within a single clock cycle.

Assuming that the loopback path stabilizes within a single clock cycle may cause problems verifying ATPG patterns or may lead to yield loss during testing.

To prevent a problem caused by this loopback, use the Add Slow Pad command to modify the simulated behavior of the bidirectional pin, on a pin by pin basis. For a slow pad, the simulation of the I/O pad is changed such that the value propagated into the internal logic is X whenever the primary input is not driven. This causes an X to be captured for all observation points dependent on the loopback value.

Arguments

pin_name

A string specifying a primary I/O pin which the tool will mark as slow.

-All

A switch specifying that the tool mark all I/O pins as slow.

-Cellcell_name

An optional switch and literal pair that specifies that the instance name of each instance of a cell of type cell_name will be added before the pin_name and each resulting name looked up as an I/O pin.

Related Commands

Delete Slow Pad

Report Slow Pads

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FastScan and FlexTest Reference Manual, V8.6_4

Page 144
Image 144
Mentor v8.6_4 manual Add Slow Pad, ∙ pinname