atmel公司24系列eeprom編程舉例-全文預覽
【正文】 abort if no acknowledgecalla, index second start for readjcshouta, addr_hi send device addressclrmovorlastart byte count in register KOUNT. Read from one byte to one page of data from an AT24Cxx.stop clear error flagincx37 get datax36:jcshouta, addr_lojcshout add fixed address programmable address to bits 3:1jc Does not wait for write cycle to plete. Write from one byte to one page of data to an AT24Cxx. clear error flagclrcjne jump if low byte not lastdph save low bytemov next byteinccjneindex, bufferb, PSIZEx77x73:djnzx74read_blocka, PADDR retry countermov Destroys A, B, DPTR, KOUNT, INDEX, ADDR_HI:ADDR_LO.retverify_page_fill:a, dpha, (LOW SIZE), x62x65:。incx65 add page size get low byte exitsetbb, x63 try to write programmable addressx63:movmovmovmovdptr, 0djnzindexindex, FILL point to buffer bytes per page First fill buffer. Writes one page at a time.x87:setb clear error flagclrcjne advance address pointerinca, FILL, x86read_currentmov jump if pare errorx82:jmpb, x81 try to read programmable addressx81:movmovmovmov through the remaining addressess. Reads and verifies one byte at a time (page mode is not used).x54:ca, (HIGH SIZE), x51dptr exitsetbb, x52 try to write programmable addressx52:movmovmovdptr, 0zdata, FILL Returns CY set to indicate write timeout.jmpjcpage_filljcbyte_fill highsp, (stack1) begin code spacereti0023H timer 1 overflow vectorreti0013H timer 0 overflow vectorreti0003Hjmp0000HDS60H40Hbuffer:BIT。EQUr1 buffer pointerkount55h bytes per AT24C64PSIZEEQU0a0h AT89Cx051 microcontroller with a 12 MHz clock. Code modifications may be。 To change the fill value, redefine FILL. To change the programmable portion。 artifacts from the debug process and serve to illustrate the use of the。 bus. Refer to the AT24Cxx family data sheets for additional information on。 address determined by the wiring of the address pins (A0, A1, A2). The。 WRITE_BLOCK and READ_BLOCK process from one byte to the number of bytes。 All five AT24Cxx device operations are supported. Byte Write, Current。 AT89C1051 by relocating or resizing the buffer and stack to fit into the。 This collection of routines allows an AT89C2051 microcontroller to read。Control_AT24Cxx 。 data buffer and stack in RAM. The code may be modified to work with the。 are special cases of functions WRITE_BLOCK and READ_BLOCK, respectively.。 The code supports multiple AT24Cxx devices per bus, each with a unique。 with the AT24Cxx fixed address (FADDR) and used to address a device on the。 Functions BYTE_FILL, VERIFY_BYTE_FILL, PAGE_FILL and VERIFY_PAGE_FILL are。 (the number of bytes per device) and PSIZE (the number of bytes per page).。 The code meets all AT24Cxx family timing requirements when executed by an。EQU
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