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Fmax of different clk edge triggering design

Altera_Forum
Honored Contributor II
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I used multiple clks and multiple edges in one design. 

 

Just wondering how does Quartus II calculate the Fmax for this case. 

 

For example: 

 

I have a critical path in clock of 400MHz, falling edge triggering: which I don't understand how Fmax is calculated. 

 

Info: Fmax is 437.83MHz (period = 2.284ns) 

Info: +Largest register to register requirement is 1.037ns 

Info: +Setup relationship between source and destination is 1.250ns 

Info: +Largest clock skew is 0.000ns 

Info: -Micro clock to output delay of source is 0.109ns 

Info: -Micro setup delay of destination is 0.104ns 

Info: -Longest register to register delay is 0.929ns 

 

Another path of 400MHz, rising edge triggering: 

Fmax = 1/period = 1/(1.668+0.109+0.104) 

 

Info: Fmax is 531.63MHz (period = 1.881ns) 

Info: +Largest register to register requirement is 2.287ns 

Info: +Setup relationship between source and destination is 2.500ns 

Info: +Largest clock skew is 0.000ns 

Info: -Micro clock to output delay of source is 0.109ns 

Info: -Micro setup delay of destination is 0.104ns 

Info: -Longest register to register delay is 1.668ns 

 

 

Thanks,
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