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Altera_Forum's avatar
Altera_Forum
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12 years ago

The virtual clock about input or output in timing constrain

When we do timing constrain in input or output, usually we need create a virtual clock. My question is, how can I know the phase relation between virtual clock and clock inside the system, in order t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

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Let's also say the board oscillator takes 1ns longer to drive the external device.

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That is what I asked. My question is:

1. how can I know in which case, the board oscillator will takes a duration (e.g. 1ns) to drive the external device?

2. Can this duration be controlled by PCB designer?

3. Where can I check it if I have a PCB?

Thanks very much.