Creo que por aqui van los tiros....
Ejemplo de programa que discrimina el pin activo, y realiza na secuencia de intermitencia en un led...
El led parpadea con distinta frecuencia dependiendo del pin pulsado.
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LIST p=16c84
#include <c:mplabp16c84.inc>
__CONFIG 11H
CONSTANT LED=0 ; PORTA pin for LED
CONSTANT CH3=7 ; CH3 corresponds to PORTB.7
CONSTANT CH2=6
CONSTANT CH1=5
CONSTANT CH0=4 ; CH0 corresponds to PORTB.4
CONSTANT VARS=0CH
LOOP1 EQU VARS+0 ; outter timing loop
LOOP2 EQU VARS+1 ; inner timing loop
LED_CNT EQU VARS+2 ; times LED is winked
ORIGINAL EQU VARS+3
NEW EQU VARS+4
CHANGE EQU VARS+5
N EQU VARS+6
ORG 000H
CLRWDT
GOTO TOP
ORG 004H
GOTO WAKE_UP
TOP:
BCF OPTION_REG, 7 ; enable internal pullups
BSF STATUS, RP0
MOVLW 0F0H ; RB.7 - RB.4 are inputs
MOVWF TRISB
BCF STATUS, RP1
BTFSS STATUS, NOT_TO ; not a watch dog timer reset
GOTO TOP_1
; sample PORTB before going to sleep
MOVF PORTB, W ; fetch the current state
MOVWF ORIGINAL ; current state in high nibble
TOP_1:
BSF INTCON, GIE ; enable general interupts
BSF INTCON, RBIE ; enable interrupt on change
L1:
SLEEP
NOP
GOTO L1
WAKE_UP: ; interrupt service routine
MOVF PORTB, W ; sample changed state of pins
MOVWF NEW ; this will become the new original
XORWF ORIGINAL, W
MOVWF CHANGE ; 1"s now in high nibble now identifies
; the bit that has changed
CLRF N ; set index to 0
BTFSC CHANGE, CH0
GOTO BLINK
INCF N, F ; N=1
BTFSC CHANGE, CH1
GOTO BLINK
INCF N, F ; N=2
BTFSC CHANGE, CH2
GOTO BLINK
INCF N, F
GOTO BLINK
BLINK: ; N is either 0, 1, 2 or 3 corresponding to the channel
; this is now mapped into a delay
CALL DELAY_LOOKUP
MOVWF LOOP1 ; save the delay in LOOP1
GOTO BLINK_AT_SPEED
DELAY_LOOKUP: ; map N into 100, 150, 200 or 250 msecs
MOVF N, W
ADDWF PCL, F
DT .100, .150, .200, .250
BLINK_AT_SPEED:
MOVLW .10
MOVWF LED_CNT
L2:
BSF PORTA, LED
CALL DELAY
CALL DELAY
BCF PORTA, LED
CALL DELAY
CALL DELAY
DECFSZ LED_CNT, F
GOTO L2
MOVF NEW, W
MOVWF ORIGINAL ; new original states
BCF INTCON, RBIF ; clear interrupt flag
RETFIE
DELAY:
L3:
MOVLW .110
MOVLW LOOP2
L4:
CLRWDT
NOP
NOP
NOP
NOP
NOP
NOP
DECFSZ LOOP2, F
GOTO L4
DECFSZ LOOP1, F
GOTO L3
RETURN
END
