list p=16f627
	
	Title "DialPhon.asm"
	
	include <p16f627.inc>
	
	cblock 0x20
		W_TEMP,STATUS_TEMP
		CALLCNTR,CALLSTATE,CMDCNTR,CMDSTATE,TONECNTR,TONESTATE
		DLYCNTH,DLYCNTL,TIMECNTR,TONECYC
	endc
	
	#define dlycmd	0x5		; delay  5ms
	#define dlytone	0x14	; delay 20ms
	#define dlybtn	0x32	; delay 50ms
	
	; Reset vector   
	org	00h
	goto	start
	
	; interrupt vector
	org	04h
	goto	interrupt
	
	; Program start
	org 05h
interrupt
   	movwf 	W_TEMP	;Save W to W_TEMP
   	swapf 	STATUS,W
   	clrf 	STATUS
   	movwf 	STATUS_TEMP

	btfss	INTCON,T0IF
	goto	endofint
	
	bcf		INTCON,T0IF
	incf	TIMECNTR,F
	movlw	0x51		; 50ms interrupt  0x51
	movwf	TMR0

endofint
   	clrf 	STATUS
   	swapf 	STATUS_TEMP,W
   	movwf 	STATUS
   	swapf 	W_TEMP,F
   	swapf 	W_TEMP,W
   	
	retfie
start
; bank1 select
	bsf	STATUS,RP0
	bcf	STATUS,RP1

	movlw	b'00000111'	; TMR0 internal clock prescale=256
	movwf	OPTION_REG
		
	movlw	b'11111111'	; PORTA All bits input	
	movwf	TRISA
	
	movlw	b'00000000'	; PORTB All bits output
	movwf	TRISB
	
; bank0 select	
	bcf	STATUS,RP0
	bcf	STATUS,RP1
	
	movlw	b'10100000'	; Global,TMR0 interrupt enable
	movwf	INTCON
	
	movlw	0x51		; 50ms interrupt  0x51
	movwf	TMR0

	clrf	PORTA
	clrf	TIMECNTR
	clrf	CMDCNTR
	clrf	CALLCNTR
	clrf	TONECNTR
	clrf	TONECYC
	bsf		CMDSTATE,0	; First Command State->'H'
	bsf		CALLSTATE,0	; First Call Button State->'H'
	bsf		TONESTATE,0	; First StopSound(Tone)input State->'H'
	
	movlw	b'10000001'	; Alarm -> off,Hook -> down
	movwf	PORTB
;	bcf		PORTB,3		; 16f74 test

DisConnect   
	movlw	b'10000001'	; Alarm -> off,Hook -> down
	movwf	PORTB
;	bcf		PORTB,3		; 16f74 test

	btfss	PORTA,0		; Receive Command ?
	goto	rcvcmdproc
	bsf		CMDSTATE,0	; Current Command State->'H'

	btfss	PORTA,2		; Call Button Push Down ?
	goto	callbtnproc1
	bsf		CALLSTATE,0 ; Current Call Button State->'H'

	goto	DisConnect

callbtnproc1	
	movlw	dlybtn
	movwf	DLYCNTH
	call	delay
	; Call Button Push Down State Reconfirm
	btfsc	PORTA,2
	goto	DisConnect	; Call Button Push Down
	
	btfss	CALLSTATE,0	; Previous Call Button State 'H'? Confirm
	goto	DisConnect

	bcf		CALLSTATE,0	; Current Call Button State->'L'
	incf	CALLCNTR,F

	movf	CALLCNTR,W
	bsf		STATUS,C
	sublw	0x0			; n>=1 ?
	btfsc	STATUS,C
	goto	DisConnect
	
	clrf	CALLCNTR
	clrf	CMDCNTR
	goto	Connect
	
rcvcmdproc
	movlw	dlycmd
	movwf	DLYCNTH
	call	delay
	; Receive Command State Reconfirm
	btfsc	PORTA,0
	goto	DisConnect
	
	btfss	CMDSTATE,0	; Previous Command State 'H'? Confirm
	goto	DisConnect

	bcf		CMDSTATE,0	; Current Command State->'L'
	incf	CMDCNTR,F
	
	movf	CMDCNTR,W
	bsf		STATUS,C
	sublw	0x78		; n>120 ?
	btfsc	STATUS,C
	goto	DisConnect
	
	clrf	CALLCNTR
	clrf	CMDCNTR
	goto	Connect
	nop
Connect
	movlw	b'11100001'	; Alarm -> on,Hook -> up
	movwf	PORTB
;	bsf		PORTB,3		; 16f74 test

	btfss	PORTA,2		; Call Button Push Down
	goto	callbtnproc2
	bsf		CALLSTATE,0	; Current Call Button State->'H'
		
	btfss	PORTA,1		; Stop Sound(Tone) input
	goto	toneproc
	bsf		TONESTATE,0	; Current StopSound(Tone) input State->'H'
	
	goto	Connect

callbtnproc2
	movlw	dlybtn
	movwf	DLYCNTH
	call	delay
	; Call Button Push Down State Reconfirm
	btfsc	PORTA,2
	goto	Connect
	
	btfss	CALLSTATE,0	; Previous Call Button State 'H'? Confirm
	goto	Connect

	bcf		CALLSTATE,0	; Current Call Button State->'L'
	incf	CALLCNTR,F
	
	movf	CALLCNTR,W
	bsf		STATUS,C
	sublw	0x0			; n>=1 ?
	btfsc	STATUS,C
	goto	Connect

	clrf	CALLCNTR
	clrf	TONECNTR
	goto	DisConnect
	
toneproc
	movlw	dlytone
	movwf	DLYCNTH
	call	delay
	; Stop Sound input State Reconfirm
	btfsc	PORTA,1
	goto	Connect
	
	btfss	TONESTATE,0	; Previous StopSound(Tone) input State->'H' Confirm
	goto	Connect

	bcf		TONESTATE,0	; Current StopSound(Tone) input State->'L' 
	
	movf	TIMECNTR,W	; Tone signal period detection 
	movwf	TONECYC
	clrf	TIMECNTR
	
	bsf		STATUS,C
	sublw	0x0b		; period > 600ms ?
	btfsc	STATUS,C
	goto	noiseproc

;;;;;;;;;;;;;;;;;;;;
;	btfss	PORTB,2		; 16f74 test
;	goto	lp0003		; 16f74 test
;	bcf		PORTB,2		; 16f74 test
;	goto	lp0004		; 16f74 test
;lp0003					; 16f74 test
; 	bsf		PORTB,2		; 16f74 test
;lp0004					; 16f74 test
;;;;;;;;;;;;;;;;;;;;

	movf	TONECYC,W
	bcf		STATUS,C
	sublw	0x0f		; period < 800ms ?
	btfss	STATUS,C
	goto	noiseproc

	incf	TONECNTR,F

	movf	TONECNTR,W
	bsf		STATUS,C
	sublw	0x5			; n>5 ?
	btfsc	STATUS,C
	goto	Connect
	
	clrf	TONECNTR
	clrf	CALLCNTR
	goto	DisConnect
noiseproc
	clrf	TONECNTR
	goto	Connect
delay			; 1ms delay loop(1 introduction cycle =1.117475us)
	nop
	movlw	0xb3
	movwf	DLYCNTL
lp
	nop
	nop
	decfsz	DLYCNTL,F
	goto	lp
	
	decfsz	DLYCNTH,F
	goto	delay
	return
	
	end