kaz1
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There seems plenty contradictions between slack equations and Timequest calculations for setup slack as well as hold slack.
for example the equation below is documented for setup:
Data RequiredTime = Latch Edge + Clock Network Delay to Destination Register – µtSU – Setup Uncertainty
but Timequest shows the following:
Thus:
conflict A: clock uncertainty is -0.030 yet it is added as negative. I expect -(-0.030) to be adding +0.030
conflict B: uTsu is 0.242 yet it is added. I expect 0.242 to be subtracted
I wonder is this editing error or some mystery internal modelling by timequest or to do with sense of +
for example the equation below is documented for setup:
Data RequiredTime = Latch Edge + Clock Network Delay to Destination Register – µtSU – Setup Uncertainty
but Timequest shows the following:
Thus:
conflict A: clock uncertainty is -0.030 yet it is added as negative. I expect -(-0.030) to be adding +0.030
conflict B: uTsu is 0.242 yet it is added. I expect 0.242 to be subtracted
I wonder is this editing error or some mystery internal modelling by timequest or to do with sense of +