//////////////////////////////////////////////////
//描述：利用定時器B 定時0.5s 使A口低四位的LED閃爍
//利用時基信號1024Hz 中斷定時1s，使IOA4--IOA7連接的LED閃爍
//硬件連接：IOA0--IOA3接4個LED 
//         IOA4--IOA7接4個LED 
///////////////////////////////////////////////////
.INCLUDE    hardware.inc
.DEFINE     RUN_TIMERB           0x0400   		//定義啟動定時器
.DEFINE     TIMER_DATA_FOR_4KHZ (0xffff - 2048) //定時0.5秒F
.DEFINE     RUN_TIMEBASE_1024    0x0010   		//時基信號1024hz中斷位
.DEFINE		TIMER_CLKA_4096		 0x0004;  		//時鐘源A 選擇4096Hz 
.RAM    
.VAR    	C_IOA_LED1,C_IOA_LED2      			//C_C_IOA_LED1為定時器B LED亮滅數據，C_IOA_LED2為時基信號LED亮滅的數據       
.VAR    	C_Clock_Cnt;       					//時基信號的計數器
.CODE
.PUBLIC 	_main
_main:
	int off 
	r1=0xffff 									//IOA口為輸出口
	[P_IOA_Attrib]=r1 
	[P_IOA_Dir]=r1 
	r1=0x00ff 
	[P_IOA_Data]=r1；	
	[C_IOA_LED1] = r1;     
	[C_IOA_LED2] = r1;
                         						//定時器B的預置數
	r1 = TIMER_DATA_FOR_4KHZ
	[P_TimerB_Data]=r1
                         						//定義使用的時鐘源頻率時鐘源A為4096Hz時
	r1 = TIMER_CLKA_4096
	[P_TimerB_Ctrl]=r1 
                         						//開放定時器B中斷和時基信號1024hz中斷
	r1 = RUN_TIMEBASE_1024 +  RUN_TIMERB  
	[P_INT_Ctrl]=r1 
	INT IRQ                  					//開IRQ中斷
              
                         						//空操作
loop:
    nop;
    goto loop;
    
//==================================================================
//定時器A中斷程序
//功能：使IOA0--IOA3位接的4個LED0.5s閃爍
//=================================================================== 
.text   
.public _IRQ2;    
_IRQ2:	
   	push r1,r5 to [sp]   						//現場保護   
   
  	r1 = [C_IOA_LED1]             				//LED 賦值
  	r1 &= 0x000f;
   	r2 = [P_IOA_Data]
   	r2 &= 0x00f0;
   	r1|=r2
   	[P_IOA_Data]=r1          
                            
  	 r1 ^= 0xffff;
   	[C_IOA_LED1] = r1; 
                            					//清中斷
   	r1=0x0400 
   	[P_INT_Clear]=r1  
                            					//恢復現場
   	pop r1,r5 from [sp]   
   	reti                     					//返回
 //===================================================================
 //1024Hz時基信號中斷
 //功能：使IOA4--IOA7接的4個LED 1秒閃爍
 //===================================================================
   
.text	
.public _IRQ4
_IRQ4:	
	push r1,r5 to [sp]							//壓棧保護；
	r1=0x0010;
	test r1,[P_INT_Ctrl];						//比較是否為1KHz的中斷源；
	jnz l_irq4_1k;								//是，則轉至對應程序段；
	r1=0x0020;				
	test r1,[P_INT_Ctrl]    					//否，則比較是否為2KHz的中斷源；	 
	jnz l_irq4_2k;								//是，則轉至對應程序段；
	
l_irq4_4k:                  					//否，則進入4KHz程序段；
   	r1 = 0x0040;
   	goto exit_int;   
           
l_irq4_2k:
   	goto exit_int;
   
l_irq4_1k:
   	r1 = [C_Clock_Cnt]
   	cmp r1,1024;
   	je LED_pro;
   	r1 += 1;
   	[C_Clock_Cnt] = r1;
   	r1 = 0x0010
   	goto exit_int;
                      							//LED賦值
 LED_pro:
   	r1 = [C_IOA_LED2]    
	r1 &= 0x00f0
   	r2 = [P_IOA_Data]
   	r2 &= 0x000f
   	r1 |= r2
	[P_IOA_Data]=r1          
   	r1 ^= 0xffff;
   	[C_IOA_LED2] = r1; 
   	r1 = 0x0000
   	[C_Clock_Cnt] = r1;  						//清時基計數器
   	r1 = 0x0010
exit_int:
   	[P_INT_Clear] = r1;   
  	 pop r1,r5 from [sp]
   	reti;