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Hello
i have a question is how to generate a delay for part of a clock cycle (for example after 0.1 of the clock cycle), since I couldn't use the wait for command for synthesis is there any way to do that in VHDL inside a process for example i want to make a <= b; but after 0.1 of the clock cycle passed, not exactly at the rising edge please if any one can helpLink Copied
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You could use a PLL to generate a phase-shifted version of your clock then pass data between the clock domains, but with a phase shift of only 10% of the clock period it may be tough to meet the setup time of the second register depending on your clock frequency. A 10x clock (also generated using a PLL) would be another option. Without more information on what you're trying to do and how fast you're running that's the best I got.
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What is the point of delay?
The fitter will insert delay from clk edge out of control as long as it passes timing. The whole idea of clk is to sample at its edge.- Mark as New
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Hi Mr. kaz
thank you for your reply the idea is that i have two signal from two process and i used them in a third process but these two signal arrive after some part of the clock cycle so i want to delay the action to some percent of the clock cycle (after 10% of the rising edge)- Mark as New
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--- Quote Start --- Hi Mr. kaz thank you for your reply the idea is that i have two signal from two process and i used them in a third process but these two signal arrive after some part of the clock cycle so i want to delay the action to some percent of the clock cycle (after 10% of the rising edge) --- Quote End --- you sample each of two signals on same one clk edge and sample result on next edge of same clk. All fpga design is based on sampling on clk edge and expecting decision to arrive at next clk edge. Inserting micro delays is not possible in current technology of FPGAs.

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