Re: Switching on P4 O/P's.

["Ross Myers" <ponty@axis.jeack.com.au>]

>What value is stored to the configuration/control register at $3FFC?
>I haven't mapped out which enable bits in 3FFC control which features,
>but it is possible that the 3FD2 PWM has it's own enable, and that in
>your case it isn't turned on.  I think I've been able to get all the PWM
>outputs to respond with $3FFC containing %1110101100011010.


Well Ludis, it turned out to be me!!.
I am using this spare O/P to switch on an external shift light.
Anyway, in my routine I'm comparing a byte value determined by me with the
actual RPM figure, but for testing I had set this value below idle so I
didn't have to rev the crap out of the motor to get results. Anyway what I
had done was use the BLS command instead of BHS, so it never branched to
switch the O/P on. All fixed now, and working great (me felling very
silly!!).
The LDD #$DFFF and STD $3FD2 works O.K.
I did notice in all the routines that Delco wrote they have a JSR to an RTS
after they write to any of the 45148 I.C's PWM O/P's. Any idea why?

Thanks,
Ross Myers

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org