topic Re: 908JK3 - clearing TOF bit. in 8-bit Microcontrollers

908JK3 - clearing TOF bit.

JimDandy — Sat, 25 Sep 2010 17:02:32 GMT

As per the manual:

"Clear TOF by reading the TIM status and control register when TOF is set and then writing a zero to TOF."

Now if the timer has overflowed I have no use for the data it now contains, so to clear the TOF bit do I still have to do a dummy read of TSC and then clear the TOF bit, or can I just clear the TOF bit and be done with it?

Re: 908JK3 - clearing TOF bit.

peg — Tue, 28 Sep 2010 04:09:29 GMT

Hello,

Yes you must still do the read.

However if you use BCLR this is a read-modify-write and so does this in one instruction.

Re: 908JK3 - clearing TOF bit.

JimDandy — Tue, 28 Sep 2010 10:03:41 GMT

Aha!

I was imagining you had to read the whole byte.

Thanks, peg.

Re: 908JK3 - clearing TOF bit.

kef — Tue, 28 Sep 2010 11:05:14 GMT

And you make CPU reading whole byte. Doing BSET/BCLR CPU still is reading and writing whole memory bytes.