topic Irregular I/O Port function in 8-bit Microcontrollers

Irregular I/O Port function

Josef — Tue, 31 Oct 2006 23:14:52 GMT

Hello,

I use the MC908GZ60 and the CodeWarrior IDE version 5.7.0

I just want all Ports A...G define as output. And switch them to 1.

Therfore I wrote this code:

#include <hidef.h> /* for EnableInterrupts macro */
#include "derivative.h" /* include peripheral declarations */

void main(void) {

EnableInterrupts; /* enable interrupts */
/* include your code here */

PTA = 0xFF;
PTB = 0xFF;
PTC = 0xFF;
PTD = 0xFF;
PTE = 0xFF;
PTF = 0xFF;
PTG = 0xFF;

DDRA = 0xFF;
DDRB = 0xFF;
DDRC = 0xFF;
DDRD = 0xFF;
DDRE = 0xFF;
DDRF = 0xFF;
DDRG = 0xFF;

for(; {
__RESET_WATCHDOG(); /* feeds the dog */
} /* loop forever */
/* please make sure that you never leave main */
}

But it doesnt work.

If i do single steps until line "DDRA = 0xFF;" nothing happens in Data1 window. The next step changes _PTA and _PTE into 63 (0b00111111)

Why this?

If i insert after the line DDRG = 0xFF;

this: PTA = 0xFF;

PTA changes into 255.

Thanks for all answers!

josef

Re: Irregular I/O Port function

nucklear — Wed, 08 Nov 2006 03:22:27 GMT

The programming or developing tool uses some lines (PTA0, PTA1, PTB0, PTB1 and PTB4) to enter monitor mode. That's why you can't debug and use those lines at the same time. If you run in stand alone mode, those lines will be available.

I experienced your same problem when running a simulation in CodeWarrior, but when tested on real hardware in stand-alone mode, it worked just fine.

Hope this helps

Re: Irregular I/O Port function

Josef — Mon, 13 Nov 2006 21:24:36 GMT

Thank you for your answer!

I will get my board in a few days and then i will test it on the real hardware.

I hope it works right there!