;Eric Melin and Brian Glassmeyer
;;***************************************
;;*** Final Project Test Code -
;;***   Test counter and Ram
;;***************************************

;Port A used for LEDs
;Port B are buttons for stepping
;Port B Pins B2 and B3 used for compare match of phone pickup
; 	pins B5, B6 are used to control ram	
;Port C 3 pins interface to counter,	
;	0 - CLR
;	1 - CLK
; 	2 - Q12 ;outbit Highest bit
;       5 pins are upper 5 bits to RAM	 
;Port D 8 Bit output data while storing
;	Buttons are 4-7
;	LEDS may be 0-3 


.include "8535def.inc"
.device  AT90S8535

.def	AnaLo	=r16    ;the lower byte of captured voltage 
.def	AnaHi	=r17	;the upper byte of captured voltage 
.def	temp	=r18	;temporary register
.def	savSREG	=r20	;save the status register
.def	cnt_bit12 =r21	;counter bit to determine if overflow 
.def	highCount =r22  ;upper 5 bits of counter
.def 	AnaCaptoggle	=r23
.def	temp = r24
.def	savSREG =r1


;**************************************
.dseg

;define variable strings to be tranmitted from RAM
outstr:  .byte    5     ;a four digit number + a zero terminate

;**************************************
.cseg

.org $0000
	rjmp 	RESET	;reset entry vector
	reti		
	reti
     	reti
	reti
	rjmp	timer1cap 	;reti
	reti
	reti
	reti
	reti    ;	rjmp    t0int
	reti		
	reti	
	reti	
	reti 	
	reti
	reti
	reti 


RESET:	
	ldi   	temp, LOW(RAMEND)   ;setup stack pointer
	out   	SPL, temp
	ldi   	temp, HIGH(RAMEND)
	out   	SPH, temp

;establish inputs and outputs
	ser	temp
	out	DDRA, temp ; LED outs
	out 	DDRD, temp ; data line
	ldi	temp, 0xF0
	out 	DDRB, temp ; pin 4 for ram R/W - 2/3 for ana comp
	ldi	temp, 0b11011111
	out 	DDRC, temp
	; load timer1 capture interrupt
	ldi	temp, exp2(TICIE1)
	out	TIMSK, temp
	ldi	AnaCaptoggle, 0

; Handle RAM control  - Write
	ldi	temp, 0x00
	out	PORTB, temp

;set up timer1 capture event
		
	sei

;init counter
INIT_CNT:   
;	ldi	temp, 0x80		;clr counter
;out	portC,temp
	rcall	Clear

;spin2:	rjmp spin2

	ldi	cnt_bit12, 0	
	ldi	highCount, 0

;High level 4calls to putBytes
;change to input 
;call to getBytes (every time input capture fires)
;
	ldi	AnaLo, 0b00000001
	rcall	putBytes
	ldi	AnaLo, 0b00000011
	rcall	putBytes
	ldi	AnaLo, 0b00000111
	rcall	putBytes
	ldi	AnaLo, 0b00001111
	rcall	putBytes
	ldi	AnaLo, 0b00011111
	rcall	putBytes
	ldi	AnaLo, 0b00111111
	rcall	putBytes
	ldi	AnaLo, 0b01111111
	rcall	putBytes
	ldi	AnaLo, 0xFF
	rcall	putBytes
	ldi	AnaLo, 0x80
	rcall	putBytes

	
	ldi	AnaLo, 0x44
	rcall	putBytes
;	sbi	PORTC, 1
;	nop
;	nop
;	sbi	PORTC, 0

	rcall	Clear  
	
;set up input from RAM
	ldi	temp, 0x10
	out	PORTB, temp

;Read data back at every external interupt
	ldi	temp, 0x00
	out 	DDRD, temp ; set up data line to input

	nop
	nop
	nop
	rcall	getBytes

	ldi	temp, 0b00001111 ; enable Timer1 Capture interupt
	out 	ACSR, temp
SPIN:	rjmp 	SPIN

putBytes:
	rcall 	INC_CNT
	out	PORTD, AnaLo
	sbi	PORTB, 4
	cbi	PORTB, 4
	com	AnaLo
	out	PORTA, AnaLo
	ret

getBytes:
	rcall   INC_CNT	
	in	AnaLo, PIND
	com 	AnaLo
	out	PORTA, AnaLo
	ret


;;Increment 12 bit counter and handle overflow for 
INC_CNT:
	sbi 	PORTC, 1  ; increment counter
	cbi 	PORTC, 1

	sbic 	PORTC, 2
	rjmp	IN_HIGH
	;input is low
	cpi	cnt_bit12, 0
	breq 	DONE_CNT
	;OVERFLOW has occured
	ldi	cnt_bit12, 0
	inc 	highCount
	cpi	highCount, 32
	breq    OUT_OF_RANGE

	mov	temp, highCount

	;NOTE - highCount == 000xxxxx 
	out	PORTC, highCount
IN_HIGH:
	ldi  	cnt_bit12, 1 	
DONE_CNT:
	ret

OUT_OF_RANGE:
	ret

Clear:
	sbi	PORTC,0
	nop
	nop
	nop
	nop
	nop
	cbi	PORTC,0
	ret

timer1cap:
	in savSREG, SREG
	clr temp
	out 	ACSR, temp 	;disable capture interupt
	
	rcall	getBytes

	cpi	AnaCaptoggle, 0
	brne	setHighComp
	ldi	AnaCaptoggle, 1
	ldi	temp, 0b00001110
	; enable Timer1 Capture interupt
	out 	ACSR, temp
	reti
setHighComp:
	ldi	AnaCaptoggle, 0
	ldi	temp, 0b00001111 ; enable Timer1 Capture interupt
	out 	ACSR, temp
	out SREG, savSREG
	reti