Hspice - how to define, probe expressions of waveforms?

[sutapanaki]

Hspice question

I usually use a different simulator -eldo, but now I need to do things with Hspice, so I hope you'll excuse me if the question is too stupid. How can I define, probe (and plot with cosmos scope) expressions of waveforms? What is the syntax? For example, a simple one as Vout/Vin to a more complex 20*log(Vin/Vout) and so on, you get the idea. In eldo I can do .defwave and the expression, but here it seems not the same. Thanks.

 

[ycj]

Hspice question

You can ".PROBE" it, ".MEASURE" it or use Cosmos scope's expression feature.

 

[sutapanaki]

Re: Hspice question

can you be just a bit more specific?

 

[engronger]

Re: Hspice question

i do not know how to realize, but i think the calculator in waveform display tools is a good choice.

ps: how to realize it in eldo?

can you be just a bit more specific?

 

[sutapanaki]

Re: Hspice question

in eldo:

.defwave gain=v(out)/v(in)

.probe ac wdb(gain)

 

[engronger]

Re: Hspice question

good
thanks

in eldo:

.defwave gain=v(out)/v(in)

.probe ac wdb(gain)

 

[ashish_chauhan]

Re: Hspice question

For sutapanaki:

.probe ac vdb(vout) vp(vout)

this gives you 20log(vout/vin) and phase of vout... assuming vin=1v (ac).

 

[sutapanaki]

Re: Hspice question

This is clear to begin with. My question was rather how to probe Vout/Vin if Vin is not 1v ac.

For sutapanaki:

.probe ac vdb(vout) vp(vout)

this gives you 20log(vout/vin) and phase of vout... assuming vin=1v (ac).