topic MC9S08DN16 port toggle error in 8-bit Microcontrollers

MC9S08DN16 port toggle error

vikassubramani — Thu, 12 Jun 2014 16:04:28 GMT

Hi every body i am new bie to this controller and i am facing some problem with my code,

i have written a small code to toggle port E I am able to toggle the port but when i run the code in debug mode and do step by step method the PC is not going set by step it is pointing to random instructions. I have included the code below please help.

/* [sample program to toggle the port E of the micro controller ] */

#include <hidef.h> /* for EnableInterrupts macro */

#include "derivative.h" /* include peripheral declarations */

void port_initialize(void);

void delay(void);

void main(void) {

EnableInterrupts;

port_initialize();

while(1)

{

PTED = 0x00; /* flashing 0's on to port E */

delay(); /* delay function */

PTED = 0xff; /* flashing 1's on to port E */

delay(); /* delay function */

PTED = 0x00; /* flashing 0's on to port E */

delay(); /* delay function */

PTED = 0xff; /* flashing 1's on to port E */

delay(); /* delay function */

PTED = 0x00; /* flashing 0's on to port E */

delay(); /* delay function */

PTED = 0xff; /* flashing 1's on to port E */

delay(); /* delay function */

__RESET_WATCHDOG();

}

void port_initialize(void )

{

PTEDD = 0xff; /* port E data direction register configured as output */

PTEPE = 0x00; /* Internal pull-up/pull-down device disabled for port E */

PTESE = 0x00; /* Output slew rate control disabled for port E */

// PTEPE = 0x00; /* Port disabled as interrupt */

}

void delay()

{

unsigned int i,j;

for(i=0; i<255; i++)

for(j=0; j<255;j++);

}

Note when i use the port just once i.e make it high and then make it low and delete the rest of the code it works find but when i try to toggle the port again by includeing the port then i am facing this problem.

Re: MC9S08DN16 port toggle error

ZhangJennie — Fri, 13 Jun 2014 05:11:48 GMT

hi vikas,

which line of you do you begin to have problem with? can you please send a screenshot of the probelm?

Best Regards,

Zhang Jun

Re: MC9S08DN16 port toggle error

vikassubramani — Fri, 13 Jun 2014 20:00:39 GMT

Re: MC9S08DN16 port toggle error

vikassubramani — Fri, 13 Jun 2014 20:02:17 GMT

Re: MC9S08DN16 port toggle error

vikassubramani — Fri, 13 Jun 2014 20:02:35 GMT

Re: MC9S08DN16 port toggle error

vikassubramani — Fri, 13 Jun 2014 20:06:08 GMT

I have tried using SPOT1_COPT = 0; disabeling the watchdog timmer but the result is the same then i removed all the comment in the code and debug even then i am facing the problem

Re: MC9S08DN16 port toggle error

ZhangJennie — Mon, 16 Jun 2014 02:35:35 GMT

hello Vikas,

the problem is due to optimization. the simple way to avoid optimization is to add "asm nop;"

while (1)

{

PTAD_PTAD0 = 1;

asm nop;

delay();

PTAD_PTAD0 = 0;

asm nop;

delay();

PTAD_PTAD0 = 1;

asm nop;

delay();

PTAD_PTAD0 = 0;

asm nop;

delay();

__Reset_Watchdog;

}

==============================================

this answer is for you. if it helps, please click on "correct answer" button. thanks!

Best Regards,

Zhang Jun

Re: MC9S08DN16 port toggle error

vikassubramani — Thu, 19 Jun 2014 19:11:54 GMT

Thanks a lot Zhang :-)

Re: MC9S08DN16 port toggle error

ZhangJennie — Fri, 20 Jun 2014 03:12:29 GMT

you are welcome!

if my answer helps, please click on "correct answer" button. thanks!

Best Regards,

Zhang Jun