Hi Folks,

Erik I understand you, but now my problem is that I can't clear KBIF.
For test purposes I reduce my code only to an interrupt detector to check the state of the KBIF. When I run this program on the simulator I can see KBIF set when the pattern match. Then the program would clear KBIF and returns from interrupt, but it goes to an infinite loop to the interrupt.
This program was tested with raisonance IDE version 6.10.15 and with uVision3 version 3.10a and the behavior is the same.

;***********************************
;* BIT DEFINITIONS
;***********************************
	IB_M BIT P0.6			; EXTERNAL INTERRUPT PIN
;***********************************
; RESET
;***********************************
        ORG 0000H
        SJMP START
;***********************************
; KEYBOARD INTERRUPT VECTOR
;***********************************
        ORG 003BH
INT_KBI:
	MOV KBCON,#00H			; CLR KBIF TO PERMIT NEXT INT. KBCON ISNT BIT ADDRESABLE
	RETI
;***********************************
; STARTS HERE
;***********************************
START:
	MOV SP,#69H                	; STACK DEFINITION = 70H - 7FH
;***********************************
; KEYPAD CONFIGURATION
;***********************************
	MOV KBMASK,#040H		; MASK FOR P0.6 ONLY
	MOV KBPATN,#000H		; INTERRUPTS WHEN 0
        MOV KBCON,#002H		        ; INTERRUPTS WITH PATTERN MATCH, KBIF=0
        MOV IEN1,#02H			; ENABLES KEYPAD INT
        MOV IEN0,#80H                	; ENABLES GLOBAL
;***********************************
;* MAIN PROGRAM 
;***********************************
MAIN_01:	
	JMP MAIN_01
;***********************************
	END 				


 

Where is the mistake?

Thanks
Roberto Muñoz