第一个代码:
//------------------------------------------------------------------------------
/// Interrupt handlers for TC interrupts. Toggles the state of LEDs
//------------------------------------------------------------------------------
char token = 0;
void TC0_IrqHandler(void) {
volatile unsigned int dummy;
dummy = AT91C_BASE_TC0->TC_SR;
if(token == 1) {
PIO_Clear(&leds[0]);
PIO_Set(&leds[1]);
token = 0;
}
else {
PIO_Set(&leds[0]);
PIO_Clear(&leds[1]);
token = 1;
}
}
//------------------------------------------------------------------------------
/// Configure Timer Counter 0 to generate an interrupt every 250ms.
//------------------------------------------------------------------------------
void ConfigureTc(void) {
unsigned int div;
unsigned int tcclks;
AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_TC0; // Enable peripheral clock
TC_FindMckDivisor(1, BOARD_MCK, &div, &tcclks); // Configure TC for a 4Hz frequency and trigger on RC compare
TC_Configure(AT91C_BASE_TC0, tcclks | AT91C_TC_CPCTRG);
AT91C_BASE_TC0->TC_RC = (BOARD_MCK / div) / 1; // timerFreq / desiredFreq
IRQ_ConfigureIT(AT91C_ID_TC0, 0, TC0_IrqHandler); // Configure and enable interrupt on RC compare
AT91C_BASE_TC0->TC_IER = AT91C_TC_CPCS;
IRQ_EnableIT(AT91C_ID_TC0);
printf(" -- timer has started \n\r");
TC_Start(AT91C_BASE_TC0);
}
它只是中断计时器,它是事件(处理程序)但是当我运行一些
while(1) {
// action
在ConfigureTc()
循环和中断定时器都冻结之后......为什么会这样?我应该添加另一个计时器并避免while(1)
吗?
while(1) {
printf("hello");
}
-- 这会打破(冻结)循环(是的,如果我不使用计时器,它会正常工作)