hramanna
Newbie level 4
I am trying to run a HSPICE simulation which involves testing for process variation and effect of noise on the circuit.
The HSPICE models that model the process variation require me to run a Monte Carlo simulation. Moreover, the models are encrypted so I cannot modify the parameters or even know what is being modified. I have to use a transient monte carlo simulation to trigger the process variation. For example, .TRAN 1ps 10ns sweep monte=100 firstrun=3, would trigger 100 instances of my circuit with different process variations for each of those instances and each instance would have a transient analysis run on it with a time step of 1ps for 10ns.
I want to now include transient noise to the above set-up. To accomplish this, I need to use ".TRANNOISE V(out) METHOD=MC SAMPLES=10 SEED=5" to create transient noise that will be added to the specified output node while performing the transient analysis. But when I include both these statements, HSPICE overwrites the second command without performing a Monte Carlo for the second command which in my case is noise. So it does not add noise at all, but only includes process variation. If I reverse the statements, then I only get noise but not the process variation.
How can I keep both the monte carlo sampling?
The HSPICE models that model the process variation require me to run a Monte Carlo simulation. Moreover, the models are encrypted so I cannot modify the parameters or even know what is being modified. I have to use a transient monte carlo simulation to trigger the process variation. For example, .TRAN 1ps 10ns sweep monte=100 firstrun=3, would trigger 100 instances of my circuit with different process variations for each of those instances and each instance would have a transient analysis run on it with a time step of 1ps for 10ns.
I want to now include transient noise to the above set-up. To accomplish this, I need to use ".TRANNOISE V(out) METHOD=MC SAMPLES=10 SEED=5" to create transient noise that will be added to the specified output node while performing the transient analysis. But when I include both these statements, HSPICE overwrites the second command without performing a Monte Carlo for the second command which in my case is noise. So it does not add noise at all, but only includes process variation. If I reverse the statements, then I only get noise but not the process variation.
How can I keep both the monte carlo sampling?