Reply by Edward Karpicz January 31, 20042004-01-31
> > > My problem is that I can't write anything to the
> > MCCNT register... the
> > > ECT datasheet says, and I quote, "Read or write
> > any time."
> >
> > Enable it first, then write to MCCNT
> >
> > Edward
> >
> >
> No, really, it isn't updating when it should. Tried
> it in the FCS full-chip simulator with modulus counter

1. "When MCEN=0, the counter is preset to $FFFF. This will
prevent an early interrupt flag when the modulus
down-counter is enabled."
So MCEN has to be set.
2. "RDMCL- Read Modulus Down-Counter Load
0 = Reads of the modulus count register will return
the present value of the count register.
1 = Reads of the modulus count register will return
the contents of the load register."

When MCEN ==0 both MC counter and MC load register are
fixed at FFFF,
load register is read only. Just try it. Setup RDMCL bit
(=1) for reads of load register.
Write any non FFFF value to MCCNT. Now enable MCEN -
MCCNT=FF.
Write again non FFFF to MCCNT and read it back.

Edward

> enabled and disabled, even though the spec says it
> should work either way.
>
> Not a big deal, I'll get it working one way or another.
>
> __________________________________
>
> --------------------To
learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu
> o learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu > ------------------------ Yahoo! Groups
Sponsor ---------------------~-->
> Buy Ink Cartridges or Refill Kits for your HP, Epson,
Canon or Lexmark
> Printer at MyInks.com. Free s/h on orders $50 or more to
the US & Canada.
> http://www.c1tracking.com/l.asp?cidU11
> http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/dN_tlB/TM
> ----------------------
-----------~->




Reply by Jeff Burgess January 31, 20042004-01-31

--- Edward Karpicz <> wrote:
> ---- Original Message -----
> From: "jb_tempe_jb" <>
>
> > My problem is that I can't write anything to the
> MCCNT register... the
> > ECT datasheet says, and I quote, "Read or write
> any time."
>
> Enable it first, then write to MCCNT
>
> Edward
No, really, it isn't updating when it should. Tried
it in the FCS full-chip simulator with modulus counter
enabled and disabled, even though the spec says it
should work either way.

Not a big deal, I'll get it working one way or another.

__________________________________



Reply by Edward Karpicz January 31, 20042004-01-31
---- Original Message -----
From: "jb_tempe_jb" <>

> My problem is that I can't write anything to the MCCNT register... the
> ECT datasheet says, and I quote, "Read or write any time."

Enable it first, then write to MCCNT

Edward



Reply by jb_tempe_jb January 30, 20042004-01-30
Hi,

I'm attempting to write some code to use the modulus down counter for
the DP256. No interrupts, simple gadfly loops looking for the
underflow flag.

Oh, yeah, I'm using code warrior 3 and writing the program in C.

My problem is that I can't write anything to the MCCNT register... the
ECT datasheet says, and I quote, "Read or write any time."

When I step through my code using the in-circuit debugger, the
register stays at its reset value of 0xFFFF.

Does anyone know if this is just a debugger problem? Or will I have
the problem in real-time? I don't have all the hardware I'm going to
need to test this yet, so I thought I'd ask you guys.

TIA,
jb