timer.c

来自「用于汇编领域的,运用于OS的MAIN函数.基于硬件基础的源代码」· C语言 代码 · 共 29 行

#include "hos.h"

void timer_isr(void);

unsigned long systick;

void timer_handler(void)
{
	systick++;

	outbyte(0x20, 0x20);	/* EOI to Master */
	outbyte(0xA0, 0x20);	/* EOI to Slave */
}

void init_timer(void)
{
	int temp = 1193180 / HZ;

	outbyte(MODECTRL, S_CNTR0 | RWLSB_MSB | TIMER_MODE3);
	outbyte(TIMER_PORT0, (temp & 0xFF));
	outbyte(TIMER_PORT0, ((temp >> 8) & 0xFF));

	systick = 0;

	set_intr_gate(0x20, &timer_isr);

	unmask_irq(0);
}