#include #include #include #include uint32_t tick=0; const uint32_t TICKS_PER_SECOND=50; extern uint32_t time; uint32_t time=0; void timer_handler(void) { tick++; if(tick==TICKS_PER_SECOND) { tick=0; time++; } ioport_out(0x20, 0x20); ioport_out(0xa0,0x20); } void init_timer(uint32_t frequency) { uint32_t divisor = 1193180 / frequency; ioport_out(0x43, 0x36); uint8_t l = (uint8_t)(divisor & 0xFF); uint8_t h = (uint8_t)( (divisor>>8) & 0xFF ); ioport_out(0x40, l); ioport_out(0x40, h); }