串行E2PROM的类型及应用

????E2PROM???à???°????
????????E2PROM?????????????????????????????÷???????????????????ò????????±????????????????????????????????????????????????????????????ú????????????·???±é??????????E2PROM°?×???????·???????????I2C×?????Microwire×????°SPI×?????????±???????Microchip???????ú?·??????????????????E2PROM?????é????????????I2C×?????????I2C×???????INTER INTEGRATED CIRCUIT BUS???????????°???????????·×????±??I2C×????????±??(SCL)??????(SDA)???ù??????????????????????·??ò????Microchip??????24XX????????E2PROM??????????128??(16??8)??256k??(32k??8)??????I2C×????á????24XX????XX??????????·??§??????1?±??????????1??24AA00/24LC00/24C00??128??I2C×???????E2PROM??????????????SDA???????????????????????ò???????????·?????????·???????????????????????????????±?è????????×è??????SCL???±?????????????÷?????????????????±????????????SDA??SCL???ù??????????·??????????????¨???·???????§???????ù??·???????±??¤??×??????ù?????±?÷???????????¤×÷?????????????ú????????×??????????ú???????????ú?ú?ú?????±??(SCL)??????×???????????·???STRAT??S
TOP??????????2?±×??????é?????????±×???????(???????±???ù±?????????)?±·????????????????????????????????????????±??(SCL)?????????±????(SDA)±???±?????±?????SCL?????????±??????(SDA)??????????±?????????????????????????(START)?????????????????????????ó?ù?????ü?????§??SCL?????????±??????(SDA)??????????±?????????????????????????(STOP)?????????????????????????ó?ù??????×÷?á??????????????????????START?ó??????????????STOP?°??SCL????????????SDA???????§????????????×????????±???????ê????×????????????????á??????ACK???±??STOP???????±???????ê????×????????????????á??????ACK????STOP?°?????á???±????ACK??????????3?±?÷???°?·????START?ó???????ú·???????????×?????????×?°ü?¨Start??(S)?????????·(7??????24XX00?????°??????1010???ó??????????)??????(R/W)??????(?°1?±???????°0?±????)?°?????á????ACK??24XX00??????×????????????? S  1  0  1  0  X  X  X  R/W  ACK????24XX00???±?à??×???????·??????§???·???????????·???·???÷????????±à??·????????ò?ú?ú?????á????ACK??????4
?±????×÷???????????ú?????????????ó????×????÷????(7??)??R/W??(?°0?±)??±í??ACK???ó??????????????×?????×????·????????????×????????ó?á??????×?????????????S????????×?(R/W?????°0?±)??ACK(?°0?±)??×????·??ACK(?°0?±)????????????ACK(?°0?±)??STOP??????5?±????×÷????????×÷???????????±?°???·?????????????¨???·?????????????¨???????·?ó??????×??????????????????±?°???·??????????S????????×?(R/W?????°1?±)??ACK????????????no ACK??STOP?????????¨???·??????????S????????×?(R/W?????°0?±)??ACK????????????ACK????????×?(R/W?????°1?±)??ACK????????????no ACK??STOP?????????¨???????·?ó??????×?????????????S????????×?(R/W?????°0?±)??ACK????????????ACK????????×?(R/W?????°1?±)??ACK??????????(1)??ACK????????????????(n??x)??noACK??STOP????24XX????????E2PROM???????????????ú????????????SCL??SDA???ù????·????ò??????????Microwire×?????????Microwire×????????±??(CLK)??????????(DI)??????????(DO)???ù?????????????????????ò????Microchip??????93XXX????????E2PROM??????????1k bit(??8/??16)??16k bit(??8/??16)??????Microwire×???
?á?????ú?·??????????CMOS?????????í??????????·??×?§???????÷?÷????????1?±????????93XX????????E2PROM???ú?·???à????????93AA46??1k 1.8V Microwire×???????E2PROM??????????????CS?????????????????????§??CS??????????93AA46??????×???????????????±à???????????ó??CS????±?????93AA46??????±à???????ê???ó????????????×???????????????????????????????CS±???????????250ns?¨TCSL)????????±????±????????????(RESET)????????CS??????????????±???????×?????????CLK???????±??????????????????CLK????????????????×????¨?±?????????è??CLK??????????DI??????????????????????×??????ú???ü???????·????????????DO??????????????????DO???è????????×è??????ORG???????á?????????????±ORG?????????±????16?á????ORG?????????±????8?á????????2?±?¤×÷?????????ù???????ú???????ü????93AA46??7?????????¤×÷????????±í??????ORG=1(??16?á??)?±???ü????(±í???°S?±??Start??)??ORG=0(??8?á??)?????????·?°??A6???ò?????·?ó???????°X?±???????à?à?????????????????????ò±à????×÷?????ì?éREADY/BUSY×????±????DO???ù????×è×?????????/????????????DO????????±í???°?
??±????????±í???°×?±????±????CS???????????±??DO??????×è??????????????????×?????????CS±????????????òDO????×??????????§??????3?±????????START(????)??????CS??DI?ù?????????óCLK?????????????????·?¨??START????????START?????óDI???????ú×?7???¤×÷?????????????ù?è???ü?????????·?°????????×é??????????±????????????ê?????????ó?????ì????????START??????DI??CLK????????×÷????????????±??¤???????±??Vcc??????1?±4V?°???ù????×÷·????ù±????????????±??????Vcc????1?±4V????????±??¤???·???????ù????×÷·????ù±????????????????±×???????????????×?????±??¤??????±??ó??????????EWEN?ü????????·????ó???????ê??????????????????????????????×÷READ???±CS?????????±???????????????ü???????·?ó????DO?????????????¨??????????(???????°)??????????×÷WRITE???±CS?????????±?????????????ü???????·?ó????DI??????????????16???ò8??????(???????°)???????????±?????????????°??CS???????°0?±(??????±????±????????250ns)??????CS???????°1?±??????×÷?????????±DO?????°1?±±????°0?±??±í??????????????×÷???°???±×????????????????????°???á×??????????????????????????±??
??×÷?ê???ó??DO??±????°1?±??±í???????????°×?±????±×????????????????ü??????????????????????????(EWDS/EWEN)??????????EWDS?ü???ó????????????×??????????í?????????????????ò????×÷???????????±×???????????????×????????±??????????????????????×÷??±?????·?EWEN?ü?????ò??·??????????ò???ü???ò???????ó??×÷????????????EWEN?ü???ó?????????????í×????????í?????????????ò????×÷????READ?ü??????EWDS??EWEN???°?ì????????????????????????????×÷(ERASE/ERAL/WRAL)??????ERASE???????????¨???·?????????????ó?????·?????????°1?±????????ERAL?????????????????????????????ó?????ù?????·???????ù???°1?±??????WRAL?ü???????¨?????????????????????????????±?????????ê?ü??????????CS???°1?±±????°0?±?????????°1?±(??????±????±????????250ns)?ó?????????ò???????????????????????ù??×????¨?±·?????×????¨?±·????????è??CLK?±????????93AA46???????ú?????????·?°???????????ò????????????????????????SPI×?????????SPI(Serial Peripheral Interface)×????????°???????§?è±?????×????±??Microchip??????25XX????????E2PROM?????ò????SPI????????×????á???????±??(SCK)?????????
?(SI)??????????(SO)???ù????????????????????????(CS)?????÷???????¨???±???÷??????SPI???????????÷????Microchip??????PIC16C6X/7X???????÷?????ù????25AA040?±??????????????SPI???????????÷???????????¨I/O???¨???í??±à????·?????????25XX040??????????25XX??????????????CMOS?????????í??????????·??×?§???????÷?÷????????25XX????????E2PROM??????????4k??(512??8)??64k??(8k??8)????????25AA040??4k??SPI×???????E2PROM??????????????1?±???????÷????CS???????????????????????§??CS????????????25AA040????????×?????CS??±??????°?ì???????????ò???????í??±à?????ê????????????????????±à???????????ó??CS????±?????25AA040??????±à???????ê???ó????????????×?????????CS??????????SO????????±?????×è???????í?à?÷??????SPI×??????????§???????ò???????óCS??????×????????????????????ò?????????ó??CS?????????????????ù????×÷?ò??????????????SCK???????±????????????×?SI???????·?ò??????SCK????????±???????SO??????????SCK?????????±??????????SI????????????????????????×??????ú???ü???????·????????????SO????????????????????????????????E2PROM?????÷???????
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????CS???????????óSCK?????????????????????????ù????????SPI×??????????ü???§?÷??????SCK??????±?HOLD??????????25AA040?è?????°±????±·???????·?HOLD?ó??????HOLD?????·???????????????????¤???ò??????CS??????????25AA040±???????°ü?¨A8???·??????8????????±???????25AA040????×?????8?????·(A7??A0)?????????????·?????????°??8?????·?ó?????¨???·????????SO?????????????????????·??????????????×??±???????????????????±????×??????????????ê±???25AA040?????????·????×?????1?????ò?????????·???±×????????·(01FFH)?????????ó?????·???????ò0000H????????????????????????CS??×?????????????×÷???????????¤???ò????????×????ò25AA040?????????°??±?????·???WREN???????????????í?????÷??????×÷????????CS???????????????ó°??±????????WREN????????25AA040???±??????8?????????????ê±??ó??????CS?????????????????????í?????÷??·???WREN?????ó????CS?????????????°???????í?????÷?????????????ò25AA040???????????????á±??????????÷?ó?????????????í?????÷?????ó??????CS??????????????·???°ü?¨A8???·??????8?????????°??8?????·(A7??A0)?????ó???????????????????????ò
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