timer.h

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

#ifndef __TIMER_H_
#define __TIMER_H_

/* Port of the 8253 register in the PC */
#define TIMER_PORT0	0x40
#define TIMER_PORT1	0x41
#define TIMER_PORT2	0x42
#define MODECTRL	0x43

/* Timer Mode */
#define TIMER_MODE0	0x00
#define TIMER_MODE1	0x02
#define TIMER_MODE2	0x04
#define TIMER_MODE3	0x06
#define TIMER_MODE4	0x08
#define TIMER_MODE5	0x0A

/* Select Counter */
#define S_CNTR0		0x00
#define S_CNTR1		0x40
#define S_CNTR2		0x80

/* Format */
#define LATCH		0x00
#define RWMSB		0x10
#define RWLSB		0x18
#define RWLSB_MSB	0x30

#define HZ		100

void timer_handler(void);
void init_timer(void);

#endif