16F88 - CCPMX strange fuse setting for HWPM

[flotulopex]

Thanks Darrel,

I thought the data-sheets where already the most difficult documents to understand... In fact, it's the whole PIC logic

How would anyone think that "1" doesn't mean "ON"? One can just not verify every and each bit setting any time he uses it, no?

BTW, I don't set any DEFINE and it works perfectly... on RB0 when the fuse is set to "OFF".

NB: just wondering how many PIC-freaks do know what you just explained...

[Darrel Taylor]

More than likely, you have manualy set the TRIS registers so that RB0 is an OUTPUT.

That's the only thing that the DEFINE's will affect.

Normally, the HPWM command will set the pin to OUTPUT on it's own, but in that case it needs the proper defines.

"PIC-freaks", you calling me a Freak?
Dang I hate when people know what I really am.
<br>

[Darrel Taylor]

Oh shoot, here's a big problem I forgot about.

If you don't set the DEFINE's, when you use the HPWM command, it will set RB3 to OUTPUT since it's the default.

If you have something providing a signal as an INPUT to RB3, it can cause a short and really screw things up.
<br>

[skimask]

Thanks Darrel,

I thought the data-sheets where already the most difficult documents to understand... In fact, it's the whole PIC logic

How would anyone think that "1" doesn't mean "ON"? One can just not verify every and each bit setting any time he uses it, no?

BTW, I don't set any DEFINE and it works perfectly... on RB0 when the fuse is set to "OFF".

NB: just wondering how many PIC-freaks do know what you just explained...

Actually, there's a lot of place where a '0' means on. Look at MCLR*. You are only doing a 'Master Clear' when the pin is at logic 0, or OFF. A lot of control signals are negative logic. On a static ram chip for instance, RD*, WR*, CS*, etc.etc. In this respect, the PIC is not as isolated a case as you might think. It's been this way for a long time. I remember when I was starting out in electronics, the whole negative logic thing was one of the more difficult things to grasp, or should I say 'accept'. But there it is...and there they'll stay...