;Expt1c.asm ;Project: Two pushes to turn on a LED ;List P = 16F84 ;#include ;__CONFIG 1Bh    ;_CP_OFF & _PWRTE_ON & _WDT_OFF & _RC_OSC ORG 0 ;This is the start of memory for the program. SetUp BSF 03,5 ;Go to Bank 1 CLRF 06 ;Make all port B output MOVLW 01 ;Load W with 0000 0001 MOVWF 05 ;Make RA0 input BCF 03,5 ;Go to Bank 0 - the program memory area. CLRF 1F ;Clear the button file CLRF 06 ;Blank the output GOTO Main Delay NOP ;Create approx 250mS delay DECFSZ 1A,1 GOTO Delay DECFSZ 1B,1 GOTO Delay RETURN Delay2 NOP ;Create 1mS debounce delay DECFSZ 1A,1 GOTO Delay2 RETURN Sw BTFSS 05,0 ;Test the push button GOTO Sw3 ;Button not pressed BTFSC 1F,2 ;Test end-of-flash flag RETURN BTFSC 1F,0 ;First pass? RETLW 00 ;No BTFSS 1F,1 ;Test first-press flag GOTO Sw2 ;First press BSF 06,0 ;Button has been pressed twice. Illuminate LED CALL Delay ;Keep LED on CALL Delay ;Keep LED on BCF 1F,1 ;Clear second-push flag bit BSF 1F,2 ;Set end-of-flash flag BCF 06,0 ;Turn LED off RETURN Sw2 BSF 1F,1 ;Set the first-press flag BSF 1F,0 ;Set button pass flag bit RETURN Sw3 BCF 1F,0 ;Clear button pass flag bit BCF 1F,2 ;Clear end-of-flash flag RETURN Main CALL Sw CALL Delay2 ;Debounce switch GOTO Main END ;Tells assembler end of program