PIC实现CRC的小程序
PIC实现Dallas的iButton通讯时，编了段产生和校验CRC的子程序。
#include
;-------------------------------
cblock 0x20
datBuff:8 ;assign 8 byte data buffer
bit_cnt ;bit counting
CRC_COUNT ;number of bytes for CRC
CRC_RESULT ;CRC resulr
crc_temp ;temporary data buffer during CRC
endc
;-------------------------------
#define skp0 btfsc
#define skp1 btfss
;===============================
org 0x000
movlw .7
movwf CRC_COUNT
movlw datBuff
movwf FSR ;FSR point to data buffer
call CRC_CHECK
movwf datBuff+7
goto $
;===============================
;CHECK THE CRC FOR ? BYTES DATA
;For the polynomial of X^8 + X^5 + X^4 + 1
;Derived from Dallas‘s iButton st 
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