keyboard.h

单片机系统开发实例

void keyboard(void) interrupt 0 using 0
{
	
	setclockcounter++;
	newkeypressed=1;//进此中断代表有键按下，置此变量为一
	P8279C=0x50;	//8279工作环境设置
	KEY_CODE=P8279D;//读键值
	KEY_CODE&=0x0f;//键值转为十六进制数字0-F
	/*处理键盘事件*/
	switch(KEY_CODE)
	{
	case KEY_DOWN://处理向下按键
		
		
		{
			if((currentmenu->menulen)<=4)
				return;
			if((currentmenu->menulen)-(currentmenu->menustart)-1<4)
				return;
			//以上为菜单向上滚动，滚动到底或到顶都应保持不动
			(currentmenu->menustart)++;
			displaymenu(*currentmenu);
			
			break;
		}
	case KEY_UP://处理向下按键
		{
			if((currentmenu->menulen)<=4)
				return;
			if(currentmenu->menustart==0)
				return;
			//以上为菜单向下滚动，滚动到底或到顶都应保持不动
			(currentmenu->menustart)--;
			displaymenu(*currentmenu);
			
			break;
		}
	case 0://按键0, 此键兼为返回键
		{
			cancelkeyflag=1;
			if(!playing)
			{
				currentmenu=&mainmenu;
				displaymenu(*currentmenu);
			}
			break;
		}
	}
	
	
	
	
	
}