.device		AT90S2313
.include	"2313def.inc"

.equ		A0	= PB3
.equ		A1	= PB2
.equ		A2	= PB1				;

.equ		PWR	= PD0				; (in)  raw 5V
.equ		ST1	= PD1				; (out) latch pll1
.equ		rot1	= PD2				; (in)  rotary sw1 to ground
.equ		ST2	= PD3				; (out) latch pll2
.equ		rot2	= PD4				; (in)  rotary sw2 to ground
.equ		RS	= PD5				; (out) LCD RS
.equ		E	= PD6				; (out) LCD E


.def		data	= r16
.def		latch	= r17
.def		temp	= r18
.def		count	= r19
.def		updn	= r20

.dseg
.equ		pll10	= 0x60
.equ		pll11	= 0x61
.equ		pll20	= 0x62
.equ		pll21	= 0x63


.cseg
		.org 0
		rjmp	main
		rjmp	int0r


main:		ldi	temp,RAMEND
		out	SPL,temp

		ldi	temp,0xff
		out	DDRB,temp			; data output
		ldi	temp,0b11101010
		out	DDRD,temp			; control port
		ldi	temp,0b00010100			; PD2,4 internal pull-up
		out	PORTD,temp

		ldi	data,0xf9			; pll1 = 0x2f9 (761)
		sts	pll10,data
		ldi	data,0x02	
		sts	pll11,data
		ldi	data,0x6f			; pll2 = 0x16f (367)
		sts	pll20,data
		ldi	data,0x01
		sts	pll21,data

		rcall	initlcd				; 
;		rcall	display				; display frequency
		rcall	initpll				; and set pll

		ldi 	temp,(1<<INT0)			; int mask0 set
		out 	GIMSK,temp
		ldi 	temp,0x00			; interrupt t0 and t1 on rising edge only
		out 	MCUCR,temp		
		ldi 	updn,0				; Start from 0
		sei					; enable interrupts and off we go!

loop:		cpi	updn,0				; main loop
		breq	loop
		brmi	dn
up:		subi	updn,1

		lds	data,pll10
		inc	data
		sts	pll10,data
		brne	up1
		lds	data,pll11
		inc	data
		sts	pll11,data
up1:		lds	data,pll20
		dec	data
		sts	pll20,data
		cpi	data,0xff
		brne	up2
		lds	data,pll21
		dec	data
		sts	pll21,data
up2:		rjmp	dn2

dn:		subi	updn,-1
		lds	data,pll10
		dec	data
		sts	pll10,data
		cpi	data,0xff
		brne	dn1
		lds	data,pll11
		dec	data
		sts	pll11,data
dn1:		lds	data,pll20
		inc	data
		sts	pll20,data
		brne	dn2
		lds	data,pll21
		inc	data
		sts	pll21,data
dn2:

		rcall	setfreq
;		rcall	display
		rjmp	loop


;**************************************************************************
;
; display frequency on LCD
;
;**************************************************************************

		lds	r21,blok
		rol	r21
		lds	r22,x
		cpi	r22,100
		brmi	a
		subi	r21,-1
		subi	r22,-100
a:		ldi	data,0
a1:		subi	r21,10
		brmi	a2
		inc	data
		rjmp	a1
a2:		subi	r21,-10
		rcall	lcdchar
		mov	data,r21
		rcall	lcdchar 
		ldi	data,0
b1:		subi	r22,10
		brmi	b2
		inc	data
		rjmp	b1
b2:		subi	r22,-10
		rcall	lcdchar
		ldi	data,'.'
		rcall	lcdchar
		mov	data,r22
		rcall	lcdchar
		rets
	


;**************************************************************************
;
; interrupt routines
;
;**************************************************************************
int0r:		push	temp
		ldi	updn,-1
		in	temp,PIND			; read physical port pins
		andi	temp,0b00010000			; leave PD4
		breq	int0r1
		ldi	updn,1
int0r1:		rcall	delay1ms
		pop	temp
		reti

;**************************************************************************
;
; MC145145 routines
;
;
; VCO1 (59.3 - 59.8) --> X --> pll1 (fr = 10.05025 kHz)
;
;                        ^
;                        |
;                        |
;
; VCO2 (51.6 - 51.9) --> X --> pll2 (fr = 9.95025 kHz)
;
;                        ^
;                        |
;                        |
;
;                       XTAL (48.0)
;
;
;
;**************************************************************************
initpll:	ldi	data,0xd2			; latch4 10MHz/9.95025kHz = 1005=0x3ed
		rcall	wrpll1
		ldi	data,0xea			; latch5=0xe
		rcall	wrpll1
		ldi	data,0x36			; latch6=0x3
		rcall	wrpll1

		ldi	data,0x32			; latch4 10MHz/10.05025kHz = 995=0x3e3
		rcall	wrpll2
		ldi	data,0xea			; latch5=0xe
		rcall	wrpll2
		ldi	data,0x36			; latch6=0x3
		rcall	wrpll2

setfreq:	lds	data,pll10			; write pll1
		swap	data
		andi	data,0xf0
		rcall	wrpll1				; latch0
		lds	data,pll10
		andi	data,0xf0
		ori	data,0x08
		rcall	wrpll1				; latch1
		lds	data,pll11
		swap	data
		andi	data,0xf0
		ori	data,0x04
		rcall	wrpll1				; latch2
		ldi	data,0x0c
		rcall	wrpll1				; latch3

		lds	data,pll20			; write pll2
		swap	data
		andi	data,0xf0
;		ori	data,0x00
		rcall	wrpll2				; latch0

		lds	data,pll20
		andi	data,0xf0
		ori	data,0x08
		rcall	wrpll2				; latch1

		lds	data,pll21
		swap	data
		andi	data,0xf0
		ori	data,0x04
		rcall	wrpll2				; latch2

		ldi	data,0x0c
		rcall	wrpll2				; latch3
		ret

wrpll1:		out	PORTB,data
		sbi	PORTD,ST1
		nop
		nop
		cbi	PORTD,ST1
		ret

wrpll2:		out	PORTB,data
		sbi	PORTD,ST2
		nop
		nop
		cbi	PORTD,ST2
		ret

;**************************************************************************
;
; read/write eeprom routines
;
;**************************************************************************




;**************************************************************************
;
; lcd routines
;
;**************************************************************************
initlcd:	ldi	data,0x20			; 4bit, 1 line
		rcall	lcdcmd
		ldi	data,0x14			; shift mode
		rcall	lcdcmd
		ldi	data,0x0c			; display on
		rcall	lcdcmd
		ldi	data,0x06			; 
		rcall	lcdcmd
		ldi	data,0x01			; clear display
		rcall	lcdcmd
		rcall	delay20ms

		ldi	count,16
		ldi	ZH,HIGH(lcdtxt*2)
		ldi	ZL,LOW(lcdtxt*2)
txtlp:		cpi	count,8
		brne	txtlp1
		ldi	data,0xc0
		rcall	lcdcmd
txtlp1:		lpm
		mov	data,r0
		rcall	lcddata
		inc	ZL
		brne	txtlp2
		inc	ZH
txtlp2:		dec	count
		brne	txtlp
		ret

lcdcmd:		cbi	PORTD,RS			; command
		push	data
		andi	data,0xf0
		rcall	lcdnib
		pop	data
		swap	data
		andi	data,0xf0
		rcall	lcdnib
		ret

lcddata:	sbi	PORTD,RS			; data
		push	data
		andi	data,0xf0
		rcall	lcdnib
		pop	data
		swap	data
		andi	data,0xf0
		rcall	lcdnib
		ret

lcdnib:		sbi	PORTD,E
		out	PORTB,data
		rcall	delay1ms
		cbi	PORTD,E
		ret

lcdtxt:		.db	"FM  70.xxx.x MHz"

;**************************************************************************
;
; other routines
;
;**************************************************************************
delay1ms:	push	r17
		push	r18
		ldi	r17,13				; 13*256*3= 9984 ticks = 1ms
del2:		ldi	r18,0xff
del1:		dec	r18
		brne	del1
		dec	r17
		brne	del2
		pop	r18
		pop	r17
		ret


delay20ms:	push	r17
		ldi	r17,20
del3:		rcall	delay1ms
		dec	r17
		brne	del3
		pop	r17
		ret

bcd2hex