使用模拟方法 读写 fm25256
sbit lcdrs = P2^2; //寄存器选择,H:数据,L:命令
sbit lcdrw = P2^1; //H:读 L:写
sbit lcdcs = P2^0; //片选
sbit fmcs1=P3^4; //EPROM片选U32
sbit fmcs2=P3^5; //EPROM片选U33
sbit fmsio=P3^6; //EPROM信号
sbit fmsck=P3^7; //EPROM时钟
const uint wren = 0x06; //set write enable latch
const uint wrdi = 0x08; //write disable
const uint rdsr = 0x05; //read status register
const uint wrsr = 0x01; //write status register
const uint read = 0x03; //read memory data
const uint write = 0x02; //write memory data