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// example to set up a millisecond timer // a millisecond counter volatile int milliseconds=0; void timer0_function( void ) { // increment milliseconds milliseconds++; } void main( void ) { // initialize interrupts irqInit(); // setup timer0 interrupt irqSet( IRQ_TIMER0, timer0_function ); // set frequency of timer 0 to 1000hz (1 second / 1000) TIMER0_DATA = TIMER_FREQ(1000); /* TIMERx_DATA sets the frequency of timer X (X being 0->3). Writing to it changes the frequency. TIMER_FREQ is a definition in libnds that divides the clock frequency by the Hz value given. Keep in mind that there is only a 16-bit counter so larger values may overflow. */ // start timer0 with interrupt enabled TIMER0_CR = TIMER_ENABLE | TIMER_IRQ_REQ; /* TIMER_ENABLE starts the timer TIMER_IRQ_REQ is the bit that enables the interrupt. */ // .... // do other things } |