SPI通信程序.doc

spi通信程序/這是主机c8051f005有硬件spi的at45db041b的讀寫驅動/ spi configuration /spi0cn = 0x02; / spi control register /msten = 1; / spi 以主方式工作 /spi0cfg = 0xc7;/ spi configuration register 第二邊沿采樣,sck空閑高 /spi0ckr = 0x00;/ spi clock rate register spiclk=24.5m/2 /spien = 1;/ spi0cn |= 0x01;sbitflash_cs= p36; union long_union /長整形聯合 unsigned long dat; unsigned intword2; unsigned char byte4;opcode;/緩沖區1單字節寫cmd=0x84void buff1_wr(unsigned int bfaddr,unsigned char dat) unsigned char i; opcode.byte0=0x84; opcode.word1=bfaddr; flash_cs=0; spi0cn&=0x03; for(i=0;i4;i+)spi0dat=opcode.bytei; while(!spif); spif=0; /連續發送4個opcode spi0dat=dat; while(!spif); spif=0; /發送第5個字節(數据) flash_cs=1; /緩沖區1單字節讀cmd=0xd4unsigned char buff1_rd(unsigned int bfaddr) unsigned char i; opcode.byte0=0xd4; opcode.word1=bfaddr; flash_cs=0; spi0cn&=0x03; for(i=0;i4;i+)spi0dat=opcode.bytei; while(!spif); spif=0; /連續發送4個opcode spi0dat=0; while(!spif); spif=0; /發送第5個任意數据字節 i=spi0dat; /清空讀緩沖器 spi0dat=0; while(!spif); spif=0; /啟動一個字節傳輸 i=spi0dat; /讀緩沖器 flash_cs=1; return(i);/main menory page program through buffer 1 or 2/completes writing into selected buffer. start self-timed erase/program operationvoid page_wr(unsigned char buff_num, unsigned int bfaddr, unsigned int paddr, unsigned char *datptr, unsigned int len) unsigned char i; opcode.dat=paddr; opcode.dat=9; opcode.dat+=(bfaddr&0x1ff); /組合opcode opcode.byte0=0x82+(buff_num-1)*3;/0x82 or 0x85 flash_cs=0; spi0cn&=0x03; for(i=0;i0;len-)spi0dat=*datptr+;while(!spif); spif=0; /連續發送len個指定數据flash_cs=1; /completes writing into selected buffer. start self-timed erase/program operation/continuous array read (opcode: 0xe8)/可從主存儲區任意地址跨頁連續讀取void array_rd(unsigned long addr, unsigned int len, unsigned char *datptr) unsigned char i; unsigned int paddr, baddr; paddr=addr / 264; baddr=addr % 264; opcode.dat=paddr; opcode.dat=9; opcode.dat+=baddr; /組合opcode opcode.byte0=0xe8; flash_cs=0; spi0cn&=0x03;for(i=0;i4;i+)spi0dat=opcode.bytei; while(!spif); spif=0; /連續發送4個op