// Copyright (c) 2017, Tobias Mueller tm(at)tm3d.de
// All rights reserved. 
// 
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//    includes software developed by tm3d.de and its contributors. 
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.comm crc16,2
.comm crc8,2
#define _CRC8_16_

CRC16_alg:
	;crc
	
	lds r_crc,crc16;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_16 ;nur schieben
	;schieben und XOR
	lds r_temp2,crc16+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_16
crc2_16:
	lds r_temp2,crc16+1
	lsr	r_temp2
	ror	r_crc
crce_16:
	sts crc16,r_crc
	sts crc16+1,r_temp2
	
	ret

.macro CRCS ; CRC beim Senden
	push r_crc
	push r_temp2
	rcall CRC16_alg
	pop r_temp2
		;crc
	lds r_crc,crc8
	mov r_temp,r_crc
	andi r_temp,0x01
	cp r_temp2,r_temp
	brne crc2_8
	lsr r_crc
	ldi r_temp,0x8c
	eor r_crc,r_temp
	rjmp crce_8
crc2_8:
	lsr r_crc
crce_8:
	sts crc8,r_crc
	pop r_crc
.endm

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

.macro CRCInit1; CRC initialisierung bei READ_COMMAND
	ldi r_temp,0
	sts crc16,r_temp
	sts crc16+1,r_temp
.endm

.macro CRCInit2; CRC initialisierung bei READ_DATA
	ldi r_temp,0
	sts crc8,r_temp
.endm