Posted on June 24, 2011 at 07:31Hi,
Port-c pc6 is connected to a 50 Hz square wave signal, the
problem is the variable cCounter did not increment in the
port_c_isr, so the PC4 pin did not toggle, please advise
about the solution.
Thanks
========================================================
#include <iostm8s903.h>
unsigned char cCounter;
void main(void)
{
CLK_ICKCR = 0x01; // high speed internal osc enable
CLK_ECKCR = 0x00; // high speed xtal osc disable
CLK_SWR = 0xE1; // select high speed internal osc as master clock
CLK_CKDIVR = 0x10; // master clk divide / 4, cpu clk div / 1
PC_ODR = 0x9E;
PC_DDR = 0x9E;
PC_CR1 = 0xFF;
PC_CR2 = 0x40; // pc6 interrupt enable
EXTI_CR1 = 0x20; // port-c interrupt falling edge only
// global interrupt enable
_asm(''rim'');
while (1)
{
while (cCounter < 25);
PC_ODR |= 0x10; // set PC4 pin
cCounter = 0;
while (cCounter < 25);
PC_ODR &= ~0x10; // clear PC4 pin
cCounter = 0;
}
}
@far @interrupt void port_c_isr(void)
{
cCounter++;
}
=====================================
stm8_interrupt_vector.c file contents
=====================================
/* BASIC INTERRUPT VECTOR TABLE FOR STM8 devices
* Copyright (c) 2007 STMicroelectronics
*/
typedef void @far (*interrupt_handler_t)(void);
struct interrupt_vector
{
unsigned char interrupt_instruction;
interrupt_handler_t interrupt_handler;
};
@far @interrupt void NonHandledInterrupt(void)
{
// in order to detect unexpected events during development,
// it is recommended to set a breakpoint on the following instruction
return;
}
extern @far @interrupt void port_c_isr(void);
extern void _stext(); /* startup routine */
struct interrupt_vector const _vectab[] = {
{0x82, (interrupt_handler_t)_stext}, /* reset */
{0x82, NonHandledInterrupt}, /* trap */
{0x82, NonHandledInterrupt}, /* irq0 */
{0x82, NonHandledInterrupt}, /* irq1 */
{0x82, NonHandledInterrupt}, /* irq2 */
{0x82, NonHandledInterrupt}, /* irq3 */
{0x82, NonHandledInterrupt}, /* irq4 */
{0x82, port_c_isr}, /* irq5 port-c exti */
{0x82, NonHandledInterrupt}, /* irq6 */
{0x82, NonHandledInterrupt}, /* irq7 */
{0x82, NonHandledInterrupt}, /* irq8 */
{0x82, NonHandledInterrupt}, /* irq9 */
{0x82, NonHandledInterrupt}, /* irq10 */
{0x82, NonHandledInterrupt}, /* irq11 */
{0x82, NonHandledInterrupt}, /* irq12 */
{0x82, NonHandledInterrupt}, /* irq13 */
{0x82, NonHandledInterrupt}, /* irq14 */
{0x82, NonHandledInterrupt}, /* irq15 */
{0x82, NonHandledInterrupt}, /* irq16 */
{0x82, NonHandledInterrupt}, /* irq17 */
{0x82, NonHandledInterrupt}, /* irq18 */
{0x82, NonHandledInterrupt}, /* irq19 */
{0x82, NonHandledInterrupt}, /* irq20 */
{0x82, NonHandledInterrupt}, /* irq21 */
{0x82, NonHandledInterrupt}, /* irq22 */
{0x82, NonHandledInterrupt}, /* irq23 */
{0x82, NonHandledInterrupt}, /* irq24 */
{0x82, NonHandledInterrupt}, /* irq25 */
{0x82, NonHandledInterrupt}, /* irq26 */
{0x82, NonHandledInterrupt}, /* irq27 */
{0x82, NonHandledInterrupt}, /* irq28 */
{0x82, NonHandledInterrupt}, /* irq29 */
};
