question about spectre ac analysis

[hsy54hsy]

when running ac analysis, the defualt circuit stage is @0s
how can I run the ac analysis using the DC bias condition @ other time, for example 200ns?
waiting for your help
thanks

 

[pavel_adameyko]

Hi, hsy54hsy
What do you think about running pss+pac analysis for your circuit?
Pls write more information why the DC point at 200 ns differs from the one at 0 s.
Regards, pavel.

 

[hsy54hsy]

because the bit control signals of one block are generated by another block after some logic canculation

Hi, hsy54hsy
What do you think about running pss+pac analysis for your circuit?
Pls write more information why the DC point at 200 ns differs from the one at 0 s.
Regards, pavel.

 

[pavel_adameyko]

because the bit control signals of one block are generated by another block after some logic canculation

You can perform transient simulation to see what values of those control signal would be, then
set them directly and perform dc and ac analysis, that's my idea (but maybe you can't do this, I don't know)
Regards.

 

[hsy54hsy]

Actually, I can run the simulation in the way you mentioned.
BUt I am too lazy to do this and want to look for a more convenient way to do this

because the bit control signals of one block are generated by another block after some logic canculation

You can perform transient simulation to see what values of those control signal would be, then
set them directly and perform dc and ac analysis, that's my idea (but maybe you can't do this, I don't know)
Regards.

 

[erikl]

Actually, I can run the simulation in the way you mentioned.
BUt I am too lazy to do this and want to look for a more convenient way to do this

See

 

[hsy54hsy]

---------- Post added at 06:41 AM ---------- Previous post was at 06:41 AM ----------

[/COLOR]nothing there

See

 

[Wu_uW]

by using trans option write final to save the DC solution. and read initial condition in ac option.

 

[erikl]

---------- Post added at 06:41 AM ---------- Previous post was at 06:41 AM ----------

[/COLOR]nothing there

Sorry hsy,
this occurred due to the big rearrangement of the EDAboard forum and all its links. Here is the new link. See my posting from 01-11-2010 06:30 PM, and kishore's answer thereafter.

 

[hsy54hsy]

Thanks a lot for your advise, magic happens:smile:

Sorry hsy,
this occurred due to the big rearrangement of the EDAboard forum and all its links. Here is the new link. See my posting from 01-11-2010 06:30 PM, and kishore's answer thereafter.