jjean
Newbie level 5
Hi all,
I had a question regarding timing from a faster clock domain to a slower clock domain, say clkA to clkB.
Consider the launching clock to be of period 2 (0,1) and the capturing clock to be of period 4 (0,2).
So, the base period is 4.
The most constraining setup check is between launch edge at 2 and capturing edge at 4.
The hold check is relative to the setup.For the setup check between 2 and 4 the possible hold checks are between
1) 2 and 0
2) 4 and 4
The most constraining is between 2 and 0 and so, this is the hold check.
But,when I report timing I see that although setup check is done correctly, hold check is done between 4 and 4, not between 2 and 0.
Is this correct? Could somebody explain this tool behaviour?
Appreciate any help.
Thanks,
jean
I had a question regarding timing from a faster clock domain to a slower clock domain, say clkA to clkB.
Consider the launching clock to be of period 2 (0,1) and the capturing clock to be of period 4 (0,2).
So, the base period is 4.
The most constraining setup check is between launch edge at 2 and capturing edge at 4.
The hold check is relative to the setup.For the setup check between 2 and 4 the possible hold checks are between
1) 2 and 0
2) 4 and 4
The most constraining is between 2 and 0 and so, this is the hold check.
But,when I report timing I see that although setup check is done correctly, hold check is done between 4 and 4, not between 2 and 0.
Is this correct? Could somebody explain this tool behaviour?
Appreciate any help.
Thanks,
jean