keyboard.c

来自「在cypress晶片上實驗讀取ps2 keyboard按鍵後顯示在lcd上,同時」· C语言 代码 · 共 39 行

#include	<pic.h>
#include	"..\delay.h"
#include 	"keyboard.h"

extern unsigned char			kb_bufs[KB_BFSIZE];
extern unsigned	int				kb_index_head, kb_index_rear;

unsigned char
kb_Getch(void)
{
	if( kb_index_head != kb_index_rear )
	{
		if( kb_index_rear < KB_BFSIZE-1 )	kb_index_rear++;
		else								kb_index_rear=0;
		return kb_bufs[kb_index_rear];
	}
	else return 0;
}

unsigned char
kb_Putch(unsigned char buf)
{
	unsigned int tmp = kb_index_head;

	if( kb_index_head < KB_BFSIZE-1 )	kb_index_head++;
	else								kb_index_head=0;

	if( kb_index_head == kb_index_rear )
	{
		kb_index_head = tmp;
		return 0;
	}
	else
	{
		kb_bufs[kb_index_head] = buf;
		return 1;
	}
}