FM24C04驱动程序.docVIP

评：驱动程序对于所有的铁电系列I2C FRAM都是适用的，只是容量、电平（3V和5V）的不同，驱动程序是针对51MCU的，但对其他MCU只要稍微修改就可使用。 在存贮数据量不大，而且读写次数频繁时，可选择I2C FRAM。/THIS CODE WAS DESIGNED TO DEMONSTRATE HOW THE FM24C04/FM24C04A SERIAL FRAM COULD /BE INTERFACED TO THE 8051 MICROCONTROLLER. THE INTERFACE USES 2 LINES /FROM PORT 2 (P2.7 AND P2.6) TO COMMUNICATE. /THE CODE SHOWN DEMONSTRATES A RANDOM READ AND BYTE WRITE. THE OTHER */MODES OF OPERATION CAN BE CREATED BY EXPANDING UPON THESE ROUTINES./深圳市华胄科技有限公司/the first date writed:2003-11-20/email:/by:tiger/=i ncludei nclude#define uchar unsigned char#define uint unsigned int#define IIC_READ 0XA1 /定义读指令#define IIC_WRITE 0XA0 /定义写指令#define NOP _nop_()/#define SDA INT0/#define SCL T0/=uchar idata buff32;/save the byte read out form iic device in test operationuchar idata readbuff32;/测试数组，暂存写入读出数据/uchar writebuff32;/=sbit SDA=P14;/P27;/THE SDA BIT IS PORT 2 BIT 7sbit SCL=P17;/P26;/THE SCL BIT IS PORT 2 BIT 6/sbit WP=P25;/sbit test=P10;/=/define a bit_operation byte to use in shift operation/use this mode can achieve high operation speed uchar bdata bbyte;/定义位操作用数组，采用此方法可提高位操作速度sbit a0=bbyte0;sbit a1=bbyte1;sbit a2=bbyte2;sbit a3=bbyte3;sbit a4=bbyte4;sbit a5=bbyte5;sbit a6=bbyte6;sbit a7=bbyte7;/=bit IFACK;/record the SDA state to confirn if ACK has happened bit NO_ACK;/no ack flagbit BUS_FAULT;/bus fault flag/=/FUNCTION:ROUTES TO PROVIDE A START SIGNALvoid start(void)SCL=0;SDA=1;SCL=1;SDA=0;SCL=0;/=/FUNCTION:ROUTES TO PROVIDE A STOP SIGNALvoid stop(void)SCL=0;SDA=0;SCL=1;SDA=1;SCL=0;/=/FUNCTION:ROUTES TO PROVIDE ACK SINGALvoid ack(void)SCL=0;SDA=0;SCL=1;SCL=0;/=/FUNCTION:ROUTES TO RELEASE THE SDA TO RECEIVE A ACK SIGNAL / OR TO PROVIDE A NO_ACK SIGNAL/type=1等待应答信号/type=0 产生无应答信号void nack(uchar type)SCL=0;SDA=1;SCL=1;IFACK=SDA; SCL=0;if(type)if(IFACK)/如果无应答信号，则置标志位NO_ACK,程序中止NO_ACK=1;/用户可以加入自己的异常处理程序/while(1);else NO_ACK=0;/=/FUNCTION:THE IIC DEVICE SHIFT OUT A BYTE TO THE MASTERuchar inbyte(void) /从IIC器件中读出数据SDA=1;SCL=1;a7=SDA;SCL=0;SCL=1;a6=SDA;SCL=0;SCL=1;a5=SDA;SCL=0;SCL=1;a4=SDA;SCL=0;SCL=1;a3=SDA;SCL=0;SCL=1;a2=SDA;SCL=0;SCL=1;a1=SDA;SCL=0;SCL=1;a0=SDA;SCL=0;return(bbyte);/=/FUNCTION:THE IIC DEVICE SHIFT IN A BYTE FROM THE MASTER void outbyte(uchar outdata) /将数据写放IIC器件bbyte=outdata;SDA=a7;SCL=1;SCL=0;SDA=a6;SCL=1;SCL=0;SDA=a5;SCL=1;SCL=0;SDA=a4;SCL=1;SCL=0;SDA=a3;SCL=1;SCL=0;SDA=a2;SCL=1;SCL=0;SDA=a1;SCL=1;SCL=0;SDA=a0;SCL=1;SCL=0;/=/FUNCTION:BYTE WRITE. add THE WRITE ADDRESS, wbyte THE DATA WANT TO WRITEvoid writebyte(uint add,uchar wbyte)/add为写入地址，wbyte为写入数据uchar temph,templ;temph=(uchar)(add/256);templ=(uchar)(add%256);start(); /开始信号outbyte(IIC_WRITE);/写命令nack(1);/等待应答outbyte(temph);/写地址nack(1);/等待应答outbyte(templ);/写地址nack(1);outbyte(wbyte);/写数据nack(1);/等待应答stop();/停止信号/=/FUNCTION:RANDOM READ.add IS THE ADDRESS WANT TO READuchar readbyte (uint add)/add为读地址uchar temp,temph,templ;temph=(uchar)(add/256);templ=(uchar)(add%256);start();/开始信号outbyte(IIC_WRITE);/写命令nack(1);/等待应答outbyte(temph);/写地址nack(1);/等待应答outbyte(templ);/写地址nack(1);start();/开始信号outbyte(IIC_READ);/读命令nack(1);/等待应答temp=inbyte();/读数据nack(0);/无应答stop();/停止信号return(temp);/=/连写函数/add为读起始地址，ptr数据保存指针,writelen为写入数据长度void writebyteseq(uint add,uchar *ptr,uint writelen)/uchar temp;uchar temph,templ;uint i;temph=(uchar)(add/256);templ=(uchar)(add%256);start(); outbyte(IIC_WRITE);nack(1);outbyte(temph);nack(1);outbyte(templ);nack(1);for(i=0;iwritelen;i+)outbyte(*(ptr+i);nack(1);stop();/=/连读函数/add为读起始地址，ptr数据保存指针,writelen为读出数据长度void readbyteseq(uint add,uchar *ptr,uint readlen)uchar temph,templ;uint i;temph=(uchar)(add/256);templ=(uchar)(add%256);start();outbyte(IIC_WRITE);nack(1);outbyte(temph);nack(1);outbyte(templ);nack(1);start();outbyte(IIC_READ);nack(1);for(i