// Copyright (c) 2017, Tobias Mueller tm(at)tm3d.de
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// 
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.comm crc,2
#define _CRC16_

CRC16_alg:
	;crc
	push r_crc
	lds r_crc,crc;lade low byte fuer vergleich mit bit
	mov r_temp,r_crc
	andi r_temp,0x01 ;nur bit 0
	cp r_temp2,r_temp  ;r_temp2 wird in interruptroutine gesetzt
	brne crc2 ;nur schieben
	;schieben und XOR
	lds r_temp2,crc+1
	lsr	r_temp2
	ror	r_crc
	ldi	r_temp, 0x01	
	eor	r_crc, r_temp
	ldi	r_temp, 0xA0	;
	eor	r_temp2, r_temp
	rjmp crce
crc2:
	lds r_temp2,crc+1
	lsr	r_temp2
	ror	r_crc
crce:
	sts crc,r_crc
	sts crc+1,r_temp2
	pop r_crc
	ret

.macro CRCS ; CRC beim Senden
	rcall CRC16_alg
.endm

.macro CRCR; CRC beim Empfangen
	;clr r_temp2
	;sbrc r_rwbyte,7
	;ldi r_temp2,1
	rcall CRC16_alg
.endm

.macro CRCInit1; CRC initialisierung bei READ_COMMAND
	ldi r_temp,0
	sts crc,r_temp
	sts crc+1,r_temp
.endm

.macro CRCInit2; CRC initialisierung bei READ_DATA
.endm