ISSUE 529

Add Proposal  Add Analysis  Edit Class, Environment, or Release
Number 529
Notify-List
Category enhancement
Synopsis Add "bidirectional skew" timing check
State open
Class enhancement
Arrival-DateJan 20 2004
Originator Shalom.Bresticker@motorola.com
Release
Environment
Description
The SDF standard includes a TIMINGCHECK construct called
BIDIRECTSKEW, which is not mentioned in the 1364 standard.

Ted Elkind wrote:

Bidirectskew was intended to anticipate a potential enhancement to
1364.

I should probably say a little more about bidirectskew. It was intended
to address the situation where two signals have skew relative to one
another, and either one could occur first. The only way the Verilog
language can address this situation at present is with 2 $skew checks
(apologies if the syntax is wrong, it's been a while):

$skew(posedge clka, posedge clkb, 6);
$skew(posedge clkb, posedge clka, 6);

Even without bidirectskew being part of 1364, the SDF bidirectskew can
still be used to annotate to $skew. For example (again, apologies for
syntax):

(bidirectskew (posege clka) (posedge clkb) (6, 7))

This would annotate 6 to the first $skew and 7 to the second $skew.
Fix
Unknown
Unformatted

Hosted by Boyd Technology