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Altera_Forum
Honored Contributor
9 years agoCan actual delays be implemented with .sdc constrains?
Hi, Can actual delays be implemented with .sdc constrains? I will try to explain what i want to achieve: Lets say i have PLL with two output clocks "pll_c0" and "pll_c1". "pll_c0" d...
Altera_Forum
Honored Contributor
9 years agoI think it is better to describe set_output_delay as defined by Synopsis.
min is the delay required from the latch edge and max is the delay required to the latch edge. Thus min equates with -tH of external device while max equates with +tSU of external device (assuming board level data delay = clock delay). Thus if we want early/late margin of data transition window then: early margin = negative of min delay figure late margin = clock period – max delay if both are zero we get early margin = 0 and late margin = clock period i.e. data can change anytime, in effect no requirement The delay figures given are just information and are then translated by fitter to whatever delays required within fpga.