Why This Program didn't go to Timer Interrupt routine?(ASM 8051)

[panda1234]

Hi,

		 ORG 00H
		 SJMP MAIN
		 ORG 03H
		 acall isr
		 MOV P2,#11111000B
		 RETI
		ORG 0BH
			LJMP T0ISR
		 ORG 60H                
MAIN:            
         MOV IE,#81H
		 MOV P2,#11111000B
		 
	 /*	 TWO DIGITS ARE STORED IN R7,R6 RESPECTIVELY .PLEASE ENTER YOUR CODE FOR FREQUENCY GENERATION HERE
		  */
           MOV TMOD,#02H
		   MOV TH0,#-50
		   SETB TR0
		   SETB EA
		   SJMP $



                    
                  

            

			SJMP MAIN
                        

              
			  
isr:	  

                 ACALL SCAN
                 MOV R7,A
                 ACALL SCAN
                 MOV R6,A
				 MOV B,R7
				 MOV A,#10
				 MUL AB
				 ADD A,R6
				 MOV R7,A      //R7 0.1 Frequency
				 ACALL SCAN
                 ACALL SCAN
                 MOV R5,A
				 ACALL SCAN
                 MOV R4,A
				 MOV B,R5
				 MOV A,#10
				 MUL AB
				 ADD A,R4
				 MOV R6,A
                 ACALL SCAN
				MOV R5,#1    //Start
                LJMP MAIN
		  JNB P2.3,$
		  JNB P2.4,$
		  JNB P2.5,$
		  JNB P2.5,$	
              	
			
		  RET
		  
		  T0ISR:
		  CPL P1.0
		  RETI
		  RETI



SCAN:
          MOV A,#11111111B                
          MOV P2,A    
          CLR P2.0        
          JB P2.3,J1
		  JNB P2.3,$   ;KEY DEBOUNCE, DELETE THIS LINE TO CHECK THE EFFECT
          MOV A,#3
          RET
   J1:
          JB P2.4,J2
		  JNB P2.4,$
          MOV A,#6
          RET
   J2:
          JB P2.5,J3
		  JNB P2.5,$	 ;
          MOV A,#9
          RET
   J3:
          JB P2.6,J4
		  JNB P2.6,$
          MOV A,#10
          RET
   J4:
          SETB P2.0
          CLR P2.1
          JB P2.3,J5
		  JNB P2.3,$
          MOV A,#2
          RET
   J5:
          JB P2.4,J6
		  JNB P2.4,$
          MOV A,#5
          RET
   J6:
          JB P2.5,J7
		  JNB P2.5,$
          MOV A,#8
          RET
   J7:
          JB P2.6,J8
		  JNB P2.6,$
          MOV A,#0
          RET
   J8:
          SETB P2.1
          CLR P2.2
          JB P2.3,K1
		  JNB P2.3,$
          MOV A,#1
          RET
   K1:
          JB P2.4,K2
		  JNB P2.4,$
          MOV A,#4
          RET
   K2:
          JB P2.5,K3
		  JNB P2.5,$
          MOV A,#7
          RET
   K3:
          JB P2.6,K4
		  JNB P2.6,$
          MOV A,#11
          RET
   K4:	  AJMP SCAN


          END

 

[FenTrac]

It looks like your code has 2 interrupt routines. One for Int0 at interrupt vector 03H and one for Timer 0 at interrupt vector 0BH. I see that in main you enable global interrupts, but I don't see interrupts enabled for timer 0 or external interrupt 0 (SETB ET0 or SETB EX0). Also, you may need to clear the interrupt flags in your service routines.

 

[FvM]

but I don't see interrupts enabled for timer 0 or external interrupt 0 (SETB ET0 or SETB EX0)

External interrupt is enabled by writing 0x81 to IE register, but timer interrupt isn't.