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Altera_Forum's avatar
Altera_Forum
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13 years ago

Fmax and Restricted Max

Hello, In the Time Quest, the Fmax for my design is 303 MHz , but the Restricted Fmax is 250 MHz with a Note that says 'limit due to minimum period restriction (max I/O toggle rate)' . The clo...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

I have a few more questions.

1) What exactly is the difference between a netlist and a timing netlist?

2) How is the Fmax and Restricted Fmax calculated? One of the report says: "Restricted fmax considers hold timing in addition to setup timing, as well as minimum pulse and minimum period restrictions. " But nothing is said about the unrestricted Fmax. Does it mean that unrestricted Fmax considers only setup time?

3) Now the restriction is only due to the width of the clock cycle and not due to the "delay" of the circuit. Will it make sense to consider Fmax and NOT restricted Fmax if we take only propagation delay into consideration?

Thank you.