Posted on March 07, 2006 at 07:22Hi,
I'm a newbe in ST7F2521 programming and I've a lot of problems using the 16-Bit timer. I've to measure the time between 2 pulses on 2 different pin (2 inputs of timerA: PF5 and PF6)
If i set the TACR1 register with 0xA0 value (enabling input capture and timer overflow interrupt) the m_woNamurTime at the and will contain always 0x0000, otherwise if i set the TACR1 = 0x80 (enabling only the Input capture interrupt) everything seems to work fine accept that I've no way to measure time bigger than the 16-bit timer.
Prescaler solution is not acceptable because i need a timer able to measure till about 20 secs.
Below there is my code; anybody has an idea?
/***************************************************/
void (* const _vectab[])() = {
NULL,
NULL,
NULL,
NULL,
NULL,
measureNamur,
NULL,
NULL,
displayModuleBusyIRQ,
displayKeyboardIRQ,
NULL,
NULL,
NULL,
NULL,
NULL,
_stext,
};
/***************************************************/
volatile WORD m_woNamurTime = 0x0000;
volatile BYTE m_byNamurIndex = 0x00;
volatile BYTE m_byTimerOverflow = 0x00;
/***************************************************/
void main(){
PFDDR = 0x00;
PFOR = 0x00;
PFDR = 0x00;
DisableInterrupts();
//External interrupt control register
ISPR0 = 0b11111100;
ISPR1 = 0b11111100;
ISPR2 = 0b11111100;
ISPR3 = 0b11111100;
EICR = 0x40;
TACR1 = 0xA0; //interrupt generated on PF5 e PF6
TACR2 = 0x00;
// Get Namur's time
m_byNamurIndex = 0x00;
m_woNamurTime = 0x0000;
m_byTimerOverflow = 0x00;
EnableInterrupts();
TACR = 0x0000;
TASR = 0x00;
while (m_byNamurIndex < 0x02){ };
TASR = 0x04;
}
/***************************************************/
@interrupt
void measureNamur()
{
BYTE byTemp = 0x00;
byTemp = TASR;
//First Sensor
if((byTemp & 0x80) && (m_byNamurIndex == 0x00))
{
m_byTimerOverflow = 0x00;
TAIC1HR = 0x00;
TAIC1LR = 0x00;
TAIC2HR = 0x00;
TAIC2LR = 0x00;
TACR = 0x0000;
TASR = 0x00;
m_byNamurIndex = 0x01;
}
//Second sensor
if((byTemp & 0x10) && (m_byNamurIndex == 0x01))
{
m_woNamurTime = (m_byTimerOverflow*256)+TAIC2HR;
TASR = 0x40;
TACR = 0x0000;
TAIC2HR = 0x00;
TAIC2LR = 0x00;
m_byNamurIndex = 0x02;
}
//Timer overflow
if((byTemp & 0x20) && (m_byNamurIndex == 0x01))
{
m_byTimerOverflow++;
}
TACR = 0x0000;
}
:-[ :-[ :-[
