Capture without CCP

[Darrel Taylor]

I spent the last 6 hours learning that when you load TMR1, you need to load TMR1H first, before TMR1L.

Yes, with RD16 set, you load the highbyte first, then when you load the lowbyte, both bytes a written to the timer at the same time.

But when reading a timer with RD16, you have to read the lowbyte first. That puts the highbyte in a buffer that can be read in the next instruction.

If you read the highbyte first, you get the value that was left in the buffer the last time you read/wrote the timer, then the lowbyte of the current timer value.

Also, when using RD16, you don't need to stop the timer when reading or writing to the timer.

For something like this where you need Critical timing ... the interrupt handlers should be ASM. Saving/Restoring PBP's system variables to get in/out of a PBP interrupt will throw the results off considerably.

None of the statements in your handlers use any PBP system variables. So you can just change the handers "type" to ASM without actually having to write it in ASM.

hth,

[boroko]

Thanks guys,

Alain, I had not thought to look at the mid-range ref manual. Seeing how they handled it helped to see it better. The longer I'm at the less I'm scared by the asm. I may not be able to write it very well, but it is getting easier to see how it works. I'm not religious about a particular method. I'm interested in results and PBP has given me the best chance to get powerful ones with the least amount of pain.

Darrel, thanks for going over these details. I was having a blind spot pulling them out of the data sheet.

It may seem like a small thing to you guys, but your assistance has helped me (and I'm sure others) get through things that in the past, would have pushed me to give up on out of pure frustration.

Bo

Wohoo! Stable numbers echoing back! Thank you so much.....

[boroko]

None of the statements in your handlers use any PBP system variables. So you can just change the handers "type" to ASM without actually having to write it in ASM.

I guess that means I don't need to include ReEnterPBP-18.bas either. Do I understand that correctly?

Bo

[Darrel Taylor]

Correct!

Including the file will use some additional RAM and program space that isn't needed.

But it won't adversely affect the program if it's there.
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