ICAP with ST72F521R9T3

[vianney]

Posted on July 23, 2003 at 10:56

ICAP with ST72F521R9T3

[vianney]

Posted on July 22, 2003 at 11:15

Hi!!

I am using ST72F521R9T3 and I try to test input capture with St7 lib.

The program works as follow: I make a Analog to Digital conversion with a potentiometer, the result is displayed on leds on port D. I inject a signal (0-5V with a frequency of 10Hz) on Timer A ICAP1 pin (PF6) so as to see if the input capture is working...

When I inject the signal on PF6 the microcontroller crash!! The value displayed on the led doesn't change when I turn the potentiometer.

Here is my code.

Does someone see a mistake??

void main (void) {

PADDR = 0x00;

PAOR = 0x0F;

PCDDR = 0x00;

PCOR = 0x00;

PFDDR=0x9F; // Timer A ICAP1 & 2 as input

PFOR=0x00; // Floating inputs

PDDR = 0x00;

PDDDR = 0xFF;

PDOR = 0xFF;

PDDR=0xFF;

PDDR=0x00;

TIMERA_Init (TIMER_FCPU_

;

ITC_Init ();

EnableInterrupts; /* Clear I bit in CC reg */

TIMERA_IT_Enable(TIMER_ICAP_IT_ENABLE); /* Enable capture interrupt */

TIMERA_ICAP_Mode(TIMER_ICAP_1,TIMER_EDGE_1); /*Detect rising edge at ICAP1 pin*/

ADC_Enable();

ADC_Select_Channel(13);

for(;

{

while(ADC_Test_Conversn_Complete()!=1)

;

PDDR=ADC_Conversn_Read();

}

}

pragma CODE_SEG DEFAULT

pragma TRAP_PROC SAVE_REGS

void interrupt 8 TIMERA_IT_Routine(void)

{

unsigned int CAP2_Value; unsigned char i,Temp;

int i1=0;

int i2=0;

if(TACSR & 0x10)

/* if(TIMERA_Status_Flag(TIMER_FLAG_ICF1)==TRUE) Call to Check ICF2 */

{

Temp = TACSR; /* Clear ICF2 */

Temp = TAIC2LR;

/* TIMERA_Clear_Flag(TIMER_FLAG_ICF2); Call to clear ICF2 */

/* call to get capture value and also clear ICF2 */

CAP2_Value = TIMERA_ICAP_Getvalue(TIMER_ICAP_2);

for(i1=0;i1<=200;i1++){

PDDR=0x01;

for(i2=0;i2

PDDR=PDDR<

}

}

}

}

Thanks for answering.

Best regards.

Junior.

[itsmejatinus]

Posted on July 23, 2003 at 01:43

Try to first initilize the input capture registers and then enable all interrupts.

[vianney]

Posted on July 23, 2003 at 10:56

Thank for your help, Ranjeet... but the problem persist.

First I thought it was a problem of interrupts management, because the program crashed only when i inject the 0-5V signal...

So I've decided to see if the microcontroller is able to detect the signal edge on the pin. So I've decided to disable interrupts, and I just check if the micrcontroller see a falling edge on PF6.

I've added a 10k pull-up resistor on PF6 (because PF6 is configured as floating input), and I inject a 0-5V signal on this pin.

I've changed my code as follows:

void TIMERA (void) ;

void main (void)

{

// Configures port D as output

PDDDR = 0xFF;

PDOR = 0xFF;

PDDR = 0x00;

// Configures PF6 as floating input

PFDDR = 0xBF;

PFOR = 0x00;

PFDR = 0x00;

TACR1=0x00; //detect a falling edge on PF6=ICAP1

TACR2=0x00;

ADC_Select_Channel (13) ;

ADC_Enable( ) ;

for( ; ; )

{

if(TACSR & 0x80==0x80){

TIMERA( ) ; //If the microcontroller detect a falling edge on PF6, then call TIMERA function

}

// Waits for the end of the conversion

while( ADC_Test_Conversn_Complete()== 0 )

;

// Reads the A/D value and writes it on the LEDs

PDDR = ADC_Conversn_Read( ) ;

}

}

#pragma CODE_SEG DEFAULT

// TIMERA Function

void TIMERA (void)

{

volatile unsigned char Temp;

int i2=0;

int i1=0;

Temp = TACSR;

Temp = TAIC1LR;

// Display a value on the leds, just to see if the program run to TIMERA function

for( i1=0;i1

PDDR=0x01;

for(i2=0;i2

PDDR=PDDR<

}

}

}

The Program never runs to the TIMERA function, I can't see anything on the leds

Can someone help me?