05-08-2009 05:06 PM
Hello you all,
i am looking for a simulation model for the Programmable Interval Timer 8253 (or similar).
I have it in an data acquisition system with whom I am working.
The point is that I need only the functionality itself. I doesn't matter if it is the same integrated circuit.
The data acquisition board is using this component and I need to simulate its functionality.
Would anybody have something to help me?
I'd appreciate any support.
Thanks in advance.
Brunno
Solved! Go to Solution.
05-13-2009 09:25 AM
Brunno,
This part in itself is a very complex programmable part - so it will be difficult to build a fully functional/accurate native SPICE model. How are you planning to interface to it within SPICE? Here are a few suggestions...
1. The datasheet does give you a good functional diagram of the counter interfaces - could you model a portion of the interface or counter/timer functionality with a specific mode of operation? http://www.intel.com/design/archives/periphrl/docs/23124406.htm
Modeling the counter/timers for a single mode of operation should not be a huge issue, modeling the control logic/command structure would likely be the more challenging endevour.
2. If you are a LabVIEW user, an alternative suggestion is to create a LabVIEW VI that would be able to closely mimic the counter/timer waveform operations you expect to generate. A nice user interface could be built in LabVIEW to emulate the various modes of operation - in this way you could use it within the Multisim simulation environment.
Details on creating LV VIs for this purpose are shown here: http://zone.ni.com/devzone/cda/tut/p/id/5635
Regards,
Patrick Noonan
05-14-2009 09:06 PM
Patrick,
based on the software I could see which mode operations were being used and the good new is that the software uses the same simple mode for all counters.
I ended up taking simple down counters to use with PLL and it seems to be working well.
Thank you for your help.
Brunno Ferraz