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标题: CRC???é?÷??ר?ù-2 AVR?????úCRC???é?????é±í???±???ú?? [打印本页]

作者: zona    时间: 2004-5-21 17:28     标题: CRC???é?÷??ר?ù-2 AVR?????úCRC???é?????é±í???±???ú??

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   ???ü????Atmega128 CRC???é?? CRC?ú??±í ??????

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????AVR???????????????ú??8??RISC MCU???????ó?à?????????è?????±?????????????ì?¨8MHz AVR????????????????200MHz 80C51??????????????32???¨???????÷?±????ALU?à?????????????????±?????????????????ò×???±à????Flash??EPPROM??????·±?à???????à????????????

????±???????Atmel??????Atmega128???????????????ú??????IEEE 1999?ê??????802.11???????ò?????é±ê×???????32?????·???à???é???¨Cyclic Redundancy Check???????????????????±?????í???é??



[???ù±?zona??2004-05-21 10:56 PM????±à??]
作者: zona    时间: 2004-5-21 17:30

1 CRC???·???à???é?????í

   1.1 ????????????????

?????ù??IEEE???¨??802.11???????ò???????é?????????????±????°??????????????????????????????????í???????????¨???????????????·?????????????á?????ü??????????????×???×é???¨???????ò×?×ó????????

?? ?· ??  ?? ??  ?? CRC???é??

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作者: zona    时间: 2004-5-21 22:32

1.2 CRC???é?????í???ú??·?·¨

????CRC???é?????à????±à??·?·¨??±????í???????é??????×÷??????n?×?????????à???????????????¨??·???????????????????g(x)???ú???à?????? m(x)????????CRC???é????c(x)??

????CRC???é????±à??·?·¨??????·???????????????g(x)?????ú???à????m(x)????×??ó???à??×÷??CRC???é???????????è??????

???? ?? ?è??·??????????é??m???????????à???? g(x)???ú???à??????r?×??m(x)?????????é???????í??r??0???????é???¤????????m+r?????????????????à??????G(x) ??

?????? ???ú???à????m(x)????G(x) ???ó???à?????×????r-1?????????à????c(x)???????????à???? c(x)????g(x)?????ú???à????m(x)±à????CRC???é????

?????? ????2??·???????c(x)???????????????à????????°ü????CRC???é??????·???×?·?????

CRC???é????100%???ì?????ù???????????ú?í?ó???¤??????????r?¨r??m(x)???×????????·??í?ó???ù????CRC???ú???à???????×?????????ó????????????????CCITT?¨?é??2048 Kb/s??PCM?ù???è±?????CRC-4·?°?????????CRC???é???ú???à????m(x)=x4+x+1 ??????16??CRC???é??????±??¤?? 1014bit????????????1????±??ì???????í?ó ????IBM?????????????·????????SDLC???????é?ò??FCS????????CRC-16?????ú???à????m(x)=x16+x15+x2+1??????CCITT?????????????????·????????HDLC???????é?ò??FCS????????CCITT-16?????ú???à????m(x)= x16+x15+x5+1??CRC-32???ú???à????m(x)=x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1??CRC-32???í????????CRC-16??10-5??????CRC-32??????????°?CRC-32??????????????????·????????ù?????¨?????????ú???ì?ò??????·???·?????????UART?¨???????????¨??MC6582??Intel8273??Z80-SIO??????????????CRC???é?????????í?????????????¨??????MPEG??????????????????CRC-32???????í??????

????m(x) ?ú???à????????????0?ò1??????m(x) ???×????????1????????????±?????1??m(x) ???????????????ì?í??????????


作者: zona    时间: 2004-5-21 22:33

2 ????Atmega128?ú??32??CRC???é??

   2.1 ?±??????·¨?ú??32??CRC???é??

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   2.2 ?é±í·¨?ú??32??CRC???é??

???????±??????·¨?à·????é±í·¨?ú??32??CRC???é?????????????????????????ì???±????????????????????????·¨?×?????ó????32??CRC?ú??±í??????1??×?????8?????ù??????±í×?????256??????????????AVR???????????????ú?????????÷????1??×??????????????ù????±à??????????????CRC?ú??±í×?????1024????·?±???0~1023????4??????1??32??CRC?ú??±í????????????????????????????????????32??CRC?ú??±í?????ò?ê??±???????????°??¨http://www.dpj.com.cn????

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3 ???é?á??

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作者: zona    时间: 2004-5-21 22:36

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作者: zona    时间: 2004-5-21 22:36

???????ù?????é?á???ù????AVR Studio4·????í????????Atmel??????Atmega128???????????????ú?????é?è±????¨????12MHz???????????????ù????

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