Casio FX-850P 8-Kanal LED-Interface

ASM

ATtiny2313 Assembler Sourcecode

; this program is testing some of the functions of the Olimex AVR-MT board


; =================
;	definitions
; =================

.include "tn2313def.inc"


.set	clock	= 10000000

; === register definitions ===
.def	w	= r16		; working register
.def	_w	= r17		; working register for interrupts
.def	a0	= r18		; argument for subroutines
.def    data = r19
.def    const = r20
.def	a	= r21
.def 	b	= r22
.def	c	= r23
.def    zaehl	= r24		; count register
.def	r	= r25





; ================== 
; 	main program
; ==================

reset:	
	ldi		w, RAMEND		; load stack pointer SP
;	ldi		w, 100
	out		SPL,w		

	ldi		w, 255		; prepare Port B for LED output
	out		DDRB, w
	out		PORTB, w

	rcall	uart_receive_init

;	rcall	wait_ms		; wait 5ms

	ldi 	const, 48
	ldi		XL, 10
	ldi		XH, 100
	


flush:									; clears UART buffer
	sbis 	UCSRA, RXC
	rjmp	main
	in 		r16, UDR
	rjmp 	flush

main:
	ldi		a,0
	ldi		b,0
	ldi		c,0
	ldi		data,0
	ldi		w,0

main2:
	ldi		zaehl, 0
	sbis 	UCSRA, RXC	; Wait for data to be received
	rjmp 	main2

	in 		w, UDR		; Get received data from buffer
	cpi		w,32		; "Preamble" 32 ?
	brne	flush		; if not...


first:	
	sbis 	UCSRA, RXC	; Wait for first data byte
	rjmp 	first
	
	in 		a, UDR		; Get received data from buffer
	
second:	
	sbis 	UCSRA, RXC	; Wait for second data byte
	rjmp 	second
	
	in 		b, UDR		; Get received data from buffer
	mov		w,b
	cpi		w,32		; "End" 32 ?
	breq	calc1		; 


third:	
	sbis 	UCSRA, RXC	; Wait for third data byte
	rjmp 	third
	
	in 		c, UDR		; Get received data from buffer
	mov		w,c
	cpi		w,32		; "End" 32 ?
	breq	calc2		; 

th3:	
	sbis	UCSRA, RXC
	rjmp	th3
	in		w, UDR
	rjmp	calc3


calc1:					; Einer

	sub		a, const
	add		data, a
	rjmp	output

calc2:					; Zehner + Einer
	sub		a, const	; Umwandlung nach dezimal
	sub		b, const

calc21:
	cpi		a, 0
	breq	calc22

	add		data, XL	; data = data + 10
	dec		a
	rjmp	calc21

calc22:
	add		data, b
	rjmp	output



calc3:					; Hunderter + Zehner + Einer
	sub		a, const
	sub		b, const
	sub		c, const

calc31:
	cpi		a,0
	breq	calc32

	add		data, XH	; data = data + 100
	dec		a
	rjmp	calc31

calc32:
	cpi		b,0
	breq	calc33

	add		data, XL	; data = data + 10
	dec 	b
	rjmp	calc32

calc33:
	add		data, c
;	rjmp 	output


output:
	mov		w, data
	com		w
	out		PORTB, w
		
	rjmp	flush
	

	
; =================== 
; 	wait routines
; ===================

wait_1000ms:			; wait 1000 miliseconds (ms)
	rcall	wait_500ms
wait_500ms:			; wait  500 miliseconds (ms)
	rcall	wait_250ms
wait_250ms:			; wait  250 miliseconds (ms)
	ldi	w,250
	rcall	wait_ms
	ret
wait_ms:			; wait  "w" miliseconds (ms)
	push	w
	rcall	wait_1000us
	pop	w
	dec	w
	brne	PC-4
	ret

wait_1000us:			; wait 1000 microseconds (us)
	rcall	wait_500us
wait_500us:			; wait  500 microseconds (us)
	rcall	wait_250us
wait_250us:			; wait  250 microseconds (us)
	ldi	w,249
	rcall	wait_us
	ret
wait_us:			; wait  "w" microseconds (us)
; in	w
	dec	w
	rcall	wait7
	brne	PC-2
	ret

wait7:	ret			; wait 7 cycles



; =========================
; 	UART receiver routines
; =========================

uart_receive_init:

	ldi		r17, 0						; 2400Baud @ 3,6864MHz
	ldi		r16, 95
	out 	UBRRH, r17					; Set baud rate
	out 	UBRRL, r16	
		
	ldi 	r16, (1<<UCSZ1)|(1<<UCSZ0)|(1<<USBS)	; Set frame format: 8data, 2stop bits
	out 	UCSRC,r16
	

	ldi 	r16, (1<<RXEN) 				; Enable receiver
	out 	UCSRB,r16

	ret