Author Topic: RAM/ROM Simulation with Microcap?  (Read 2014 times)

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Offline marcopoloTopic starter

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RAM/ROM Simulation with Microcap?
« on: February 23, 2021, 11:04:17 am »
Hello,

Do you know if it's possible with Micro-Cap to simulate RAM and ROM with an init file?

Thanks,
Marc
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Offline oliviasmithh900

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Re: RAM/ROM Simulation with Microcap?
« Reply #1 on: March 04, 2021, 12:36:04 am »
RAM may be but ROM no chance ...  |O
 

Online SiliconWizard

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Re: RAM/ROM Simulation with Microcap?
« Reply #2 on: March 08, 2021, 02:21:42 am »
I haven't seen any way of simulating a RAM or ROM with Microcap, so let alone specifying an init content for them. Haven't found a corresponding digital part or primitive.
You may be able to design memory blocks using the digital primitives, although I expect this to be pretty tedious. See the reference manual for more info on digital primitives.

What would you want to simulate RAM or ROM for?
 

Offline marcopoloTopic starter

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Re: RAM/ROM Simulation with Microcap?
« Reply #3 on: March 08, 2021, 07:52:02 am »
I would like to simulate a TTL microcoded cpu with 74181 and 74182
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Offline DiTBho

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Re: RAM/ROM Simulation with Microcap?
« Reply #4 on: March 08, 2021, 01:23:38 pm »
I would write a RTL model and simulate it  :D
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Offline marcopoloTopic starter

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Re: RAM/ROM Simulation with Microcap?
« Reply #5 on: March 08, 2021, 02:48:17 pm »
Yes, but the next step is the build of the simulated computer with TTL IC.
It's easier to start from an simulated schematic than to convert Verilog code to schematic even if I use TTL models in Verilog.
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Online SiliconWizard

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Re: RAM/ROM Simulation with Microcap?
« Reply #6 on: March 08, 2021, 06:02:02 pm »
I see. As I said, no RAM or ROM to be found in Microcap, so your only bet would be to implement static memory, for instance using flip-flop primitives. You'll need to know how to design subcircuits, how to use digital primitives... and then, flip-flops can get an initial value, but managing to initialize your custom memory subcircuits from a file, yeah... maybe using "file stimulus" to preload  your memory cells during the initial phase of the simulation?

Now maybe someone more expert with Microcap has a better idea.

 

Offline marcopoloTopic starter

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Re: RAM/ROM Simulation with Microcap?
« Reply #7 on: March 08, 2021, 07:42:11 pm »
The RAM problem can be solved with 74ls670 but not the ROM problem.
I'll look for another software for this project, maybe an old ALTERA Quartus in schematic mode with its library of TTL circuits.

If anyone has any ideas, they are welcome  :)
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Offline marcopoloTopic starter

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Re: RAM/ROM Simulation with Microcap?
« Reply #8 on: April 19, 2021, 01:38:27 pm »
This software can simulate TTL IC, RAM and ROM:
https://github.com/hneemann/Digital
My Archives (68K, Old logic, SSB radio): marc.retronik.fr
 
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