FastScan and FlexTest Reference Manual, V8.6_4
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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.
•-Cell cell_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