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model for TTL

Hi all,
 
I need to edit TTL models: to change thresholds, to connect Vcc and GND and to describe them (VCC and GND) in the model.
How to do that?
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I could be wrong, but it seems to me that these are modeled using VHDL. Unless you know how to use VHDL, I don't know how you could edit them.

One option is to look for a model on the internet for the component that you need then edit that. This is all I have on this subject..I'm sure Nestor or Knoblish would know more.

Sorry I couldn't be of much help. Have a nice day.

Kittmaster's Component Database
http://ni.kittmaster.com

Have a Nice Day
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Hi Vladimir,

If you're talking about components in the "TTL" group, then you're talking about digital models. Digital models use logic states and understand nothing of voltages and currents. They go to and from their domain through a special bridge device (which is hidden from schematic capture). It is this bridge element that contains parameters responsible for input thershold and output voltage levels.

If your setting under simulate->digital simulation settings is set to "Ideal", you will not be able to alter these values with schematic capture simulation. If it is set to "Real", you can set the output voltage levels only by placing appropriate power supplies on the schematic. Just double click on component and goto "pin" tab to see what power rails it looks for (VCC, VDD, VSS, VEE, GND). Then choose and place these from the database.

Thanks,




Max
National Instruments
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there will be a DevZone article about this very soon. I will post in this thread when it appears.


Max
National Instruments
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