Replace PBP with Assembly concerning Timer0

[mister_e]

Hi selbstdual,

what do you need to count exactly? Events, internal clock tick, amount of hair lost in the process?

Well.. what's your current project?

[selbstdual]

Hair ? Is this a joke ? I kept on laughing the whole day. Very funny.

It is about counting the time until CMCON.6 gets a high level.

[Acetronics2]

Just connect pin 2 (C1OUT) to pin 9 or 12 ... and read TMR1H and TMRIL just when needed ...

Details are in that ****ING DATA SHEET... fig 7.1

Alain

PS: No hair lost ... was a pleasure !!!

[mister_e]

OR, stop the timer on a comparator interrupt...

In meantime, is there a specific time range?

I'll be back...

[selbstdual]

There is no TMR1H and L as TMR0 is 8 Bit. I cannot use TMR1 as I am using the compare-module. Additionally, Pin2 and Pin12 are used.

I would need to check for the timer to overflow in the loop instead of reading its value. As basic is not machinecode I don't know how many tics I am missing by that method, you know ...

MisterE: Interrupts are disabled(INTCON = 0), I am just looking at the 'time' it takes for the comparator's output to change.

What do you mean by time range ?

Before we go too much into detail here: Using my method compared to the built in timer, how many more ticks does the built in timer notice ?

[mister_e]

What do you mean by time range ?

Min and Max expected delay between the time you Start the Timer and 'till the comparator's output will change.

Before we go too much into detail here: Using my method compared to the built in timer, how many more ticks does the built in timer notice ?

Hard to say, but it can be measured with a scope + extra I/O OR by using something like Darrel suggested bellow...
http://www.picbasic.co.uk/forum/showthread.php?t=365

i'll do something simple here to help you to start. i think you're not as this far anyway.

stay tunned

[selbstdual]

Currently I get values between 1800 and 400 for 'Value'. Whatever, don't hurry to answer this question because my current implementation works already. This is just for finetuning...

[sougata]

Hi,

I would prefer using interrupts.

Your TIMER_ZERO is already a word variable. So on a timer zero interrupt you can just increment the HighByte of the variable and normally dump the TMR0 to the lowbyte. This would make a pseudo 16bit timer. On a comparator interrupt, get the readings. It should not be very difficult in ASM . By the way what is your clock frequency and your timer0 prescaler value ? If you are using a high prescale then Darrel's Instant Interrupt may work.