;Expt11b.asm ;Project: Whistle-On Whistle-Off ;List P = 16F84 ;#include ;__CONFIG 1Bh    ;_CP_OFF & _PWRTE_ON & _WDT_OFF & _RC_OSC ORG 00 ;Start of memory for program. SetUp BSF 03,5 ;Go to Bank 1 CLRF 06 ;Make all port B output MOVLW 02 ;Load W with 0000 0010 MOVWF 05 ;Make RA1 input BCF 03,5 ;Go to Bank 0 - the program memory area. CLRF 1F ;Clear flag file CLRF 05 ;Clear the display CLRF 06 ;Clear the display GOTO Main Delay NOP ; Create 1mS delay DECFSZ 1A,1 GOTO Delay RETURN Delay1 MOVLW 40h MOVWF 1B DelayA DECFSZ 1A,1 GOTO DelayA DECFSZ 1B,1 GOTO DelayA RETURN Look BCF 1F,0 ;Clear the "whistle" flag MOVLW 040h ;Number of loops MOVWF 0E ;Loops file CLRF 0Ch ;Holds the LOW count Look1 CALL Delay BTFSC 05,1 GOTO look2 INCF 0Ch,1 ;LOW detected Look2 DECFSZ 0E,1 GOTO Look1 MOVLW 18h SUBWF 0Ch,0 BTFSS 03,0 ;Test Carry flag. If set C=more than 10h RETURN BSF 1F,0 ;Whistle detected RETURN Main CALL Look BTFSS 1F,0 GOTO Main ;No whistle MOVLW 04 ;Whistle - turn on display MOVWF 05 Main1 CALL Delay1 CALL Look BTFSC 1F,0 GOTO Main1 ;whistle Main2 CALL Delay1 CALL Look BTFSS 1F,0 GOTO Main2 ;No whistle MOVLW 00 ;Whistle - turn off display MOVWF 05 Main3 CALL Delay1 CALL Look BTFSC 1F,0 GOTO Main3 ;whistle GOTO Main ;no whistle END ;Tells assembler end of program