clocks


Felix

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thing is, the pic is already programmed.  i am trying to interface into it without modifying its program.

 

i just don't know if its possible to run zpuino and generate a 4MHz clock with zpuino at the same time.

 

heck i dont even know if its possible to *accurately* generate a 4MHz clock with zpuino by itself.

 

i would think not, but i figure it doesnt hurt to ask.

 

i will most likely wait for my caps/xtal to come in the mail in a few days and do it that way, but was hoping for

an all in one solution.  short of adding in a 2nd pic just for clock which would be kind of dumb :)

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Felix:

 

the best way to generate the 4MHz clock is to program the 16-bit timer w/o prescaler to provide a 50% duty cycle PWM.

 

From top of my head, set the CMP to 23 ((96000000/4000000)-1), and set the CMPLOW of the relevant PWM output to 0, and CMPHIGH to 12.

 

I can write a simple sketch that does this for you later today, if you are kind enough to tell me to which FPGA pin you'll be expecting the clock output.

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