Instant Interrupts - Revisited

[Darrel Taylor]

Chris,

For the examples, I simply used the timers overflow to TOGGLE a pin, so the duty cycle is always 50%. But then, it's just an example. If you increase the frequency of the timer Overflows, either by reducing the prescaler, or by re-loading the timer on each interrupt, or both, you can control the duty cycle within the interrupt handler. By incrementing a variable you can have it turn on for 10 interrupts and off for 246, or whatever resolution you want.
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[Charles Linquis]

Darrel,

Thanks for the clarifications.

I'm not very familiar with bank switching, so at this time I didn't feel comfortable with dealing with that. You mention "CHK?RP" as an easy way to deal with the issue. I have no idea how to use this. I assume this is a macro that comes from somewhere. Could you please elaborate?

[mister_e]

CHK?RP is a PBP macro wich send you to the correct bank of a x register

CHK?RP PORTA

not much, using this one avoid you to read the x PIC datasheet to see where the x register is placed and do the bank switching yourself. Really handy stuff!

[Bruce]

Nice work Darrel.

[Darrel Taylor]

Bruce,

Thank You, Thank You, Thank You!

But I gotta ask.

Have you tried it yet?
Or does it just Look Cool?

Apprehensively,
&nbsp; Darrel

[Bruce]

Hi Darrel,

I've tested it on a Lab-X1 with 18F452. Timers 0, 1 and 3 hi-pri. USART rx
low-pri, and it works as advertised...;o}

P.S. I thought this was pretty slick;
movff FSR#v(F)L, fsave#v(F)Pr
movff FSR#v(F)H, fsave#v(F)Pr + 1

[Darrel Taylor]

Excellent!

Thanks for that.

And, yeah. The "Text Substitution" comes in pretty handy.
A bit Cryptic looking, but it is "Slick". Finding more uses for it with each new program.
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