PSpice: Possibility to initialize flipflops randomly

Sorry Norbert, but those are the options. Usually, you should use 'X', as this basically says that, until the FF is TOLD what state it should be, it doesn't have a state. Most set them all to 0 or 1, (usually 0) to not have to go through the trouble of initializing everything.

Charlie

Thanks for your response Charlie.

I know that I can force all FFs to 0 or 1 default state in order to simplify the simulation circuit.

But I want to find out if I need initial resets in the REAL circuit where I have to expect random initial FF states.

Thanks for your response Charlie.

I know that I can force all FFs to 0 or 1 default state in order to simplify the simulation circuit.

But I want to find out if I need initial resets in the REAL circuit where I have to expect random initial FF states.

Hello Norbert,

This will require that you set every possible combination as a start condition. It's useless to rely on what a programmer of PSPICE has decided for the default at startup.

Best ergards, Helmut

If your circuit can exhibit untoward behavior during a random start I usually design so that the desired sequence can be reached in a few clock cycles, or include a RESET sequence in the state machine.

...Jim Thompson

I think .IC will work with the digital.

...Jim Thompson

Sure! I also did so and it looks like it works. I also wanted to find a comfortable way to verify that.

Sure! I also did so and it looks like it works. But I wanted to find a comfortable way to verify that.

Yep. I'm with you. It's hard, sometimes, to convince yourself that you haven't missed a lock-up state ;-)

...Jim Thompson

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