What is the slack in synthesis results of SynplifyPRO?

[ahmadagha23]

synplifypro sythesizer

Hi
what is slack in synthesis results?

and how can I can understand RTL schematic results of synplifypro7.5?

thanks from your help

 

[eda_wiz]

synplifypro sythesizer

Slack = Required Time of a signal at point(to tun at a particular frequency) - Actual arrival time of the signal.
A negative slack means.. your circuit wont run at the requested frequency.

 

[ahmadagha23]

Re: synplifypro sythesizer

Hi
I know but why it used?


thanks

 

[Kukaz]

synplifypro sythesizer

probably, must have : "your circuit won't run ..."
It changes a situation ?

Kukaz.

 

[wadaye]

Re: synplifypro sythesizer

Hi
I know but why it used?


thanks

The slack is used for set/hold check, if the slack is negative, your circuit

can't run at the timing your want.

wang1

 

[ahmadagha23]

Re: synplifypro sythesizer

Hi
If the slack is negative I must change my circuit design or must change frequency requirement?

Why if I choose automatice frequency requirment mode for synthesis operation sometimes it give me negative slack times?

thanks?

 

[wadaye]

Re: synplifypro sythesizer

Hi
If the slack is negative I must change my circuit design or must change frequency requirement?

Why if I choose automatice frequency requirment mode for synthesis operation sometimes it give me negative slack times?

thanks?

Hi ahmadagha23:

Yes, you have to modify you design or timing requirement to make the

slack>=0.

wang1