//======================================================
// 文件名稱:	PWM.asm
// 功能描述：   PWM設(shè)置服務(wù) 
// 完成日期：   2003-8-13
//======================================================
.define		P_INT_CTRL		0x7010;
.define		P_INT_CLEAR		0x7011;
.EXTERNAL   _F_PwmIRQ3
.RAM
                           //TimeA: 頻率設(shè)置值,PWM:占空比設(shè)置值
.VAR TimeA=0x0020,PWM=0x0000
.text
//======================================================
// 函數(shù)名稱:	IRQ3
// 實現(xiàn)功能:    外部中斷服務(wù)
// 入口參數(shù)：   無
// 出口參數(shù)：   無
// 破壞寄存器:  r1，r2
//======================================================
.public _IRQ3
_IRQ3:
   push r1,r5 to [sp]		//壓棧保護(hù) 
   r1=0x0100 	    
   test r1,[P_INT_CTRL] 	//比較是否為IRQ3_EXT1	 
   jnz  irq3_ext1			//是，則轉(zhuǎn)至對應(yīng)程序段；
   r1=0x0200 	    
   test r1,[P_INT_CTRL] 	//否，則比較是否為IRQ3_EXT2
   jnz  irq3_ext2			//是，則轉(zhuǎn)至對應(yīng)程序段；
   r1=0x0200 	    
   
irq3_key:					//否，則進(jìn)入鍵喚醒中斷
	r1=0x0080 	     
	[P_INT_CLEAR]=r1 
	pop r1,r5 from [sp]   
	reti

irq3_ext2:
   r1=[TimeA]
   r1+=0xf0
   [TimeA]=r1
   r2=[PWM]
   call _F_PwmIRQ3;          //重設(shè)pwm,來自于pwm.asm
   r1=0x0200 	     
   [P_INT_CLEAR]=r1 
   pop r1,r5 from [sp]
   reti

irq3_ext1:
   r1=[PWM]
   r1+=0x0030
   r2=0x0ff0
   cmp r2,r1
   jb ReturnLoop 
   [PWM]=r1
   r1=[TimeA]
   r2=[PWM]
   call _F_PwmIRQ3;          //重設(shè)pwm,來自于pwm.asm
   r1=0x0100 	     
   [P_INT_CLEAR]=r1 
   pop r1,r5 from [sp]
   reti
ReturnLoop:
   r1=0x0000
   [PWM]=r1
   r1=[TimeA]
   r2=[PWM]
   call _F_PwmIRQ3;          //重設(shè)pwm,來自于pwm.asm
   r1=0x0100 	     
   [P_INT_CLEAR]=r1 
   pop r1,r5 from [sp]
   reti