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标题: 以C语言完成读写24LCxx系列的EEPROM的实例 [打印本页]

作者: winnie 时间: 2009-5-6 10:09
标题: 以C语言完成读写24LCxx系列的EEPROM的实例
//************************************************************************
//*          Using I2C Master Mode for access Slave (EEPRM)
//*
//* Written by:  Richard Yang
//*             Sr. Corporate Application Engineer
//*             Microchip Technology Inc.
//* Date:       Oct. 3nd '2002
//* Revision: 1.00
//* Language tools : MPLAB-C18 v2.09.13
//*    MPLINK v3.10
//*    MPLAB-IDE v6.00.17 & ICD2
//************************************************************************
/* Include Header files  */

#include <p18f452.h>
#include <i2c.h> // Load I2C Header file from defult direct
#include <timers.h>
#include "P18LCD.h" // Load P18LCD Header file form current working direct

/* Declare the Function Prototype */

void Initialize_I2C_Master(void);
void EE_Page_Write(unsigned char,unsigned char,unsigned char,unsigned char *);
void EE_SEQU_Read(unsigned char,unsigned char,unsigned char,unsigned char *);
void EEPROM_Write(unsigned char,unsigned char,unsigned char);
void EEPROM_ACK(unsigned char);
unsigned char EEPROM_Read(unsigned char,unsigned char);
void I2C_Done(void);
void Initialize_Timer2(void);
void isr_high_direct(void);
void isr_high(void);

#pragma romdata My_romdata=0x1000
const rom far unsigned char LCD_MSG1[]="SW2: Byte Write ";
const rom far unsigned char LCD_MSG2[]="SW6: Random Read";
const rom far unsigned char LCD_MSG3[]="Byte Write Mode ";
const rom far unsigned char LCD_MSG4[]="Random Read Mode";
const rom far unsigned char LCD_MSG5[]="Sended:       ";
const rom far unsigned char LCD_MSG6[]="Send:          ";
const rom unsigned char I2C_Write_Buffer[]="Microchip Technology";
#pragma romdata

/* Define following array in data memory */

unsigned char I2C_Read_Buffer [32];

/* define following variable in data memory at Access Bank */
#pragma udata access My_RAM
near unsigned char Debounce;
near unsigned char Send_Addr;
near unsigned char Send_Data;
near unsigned char Send_Length;
near unsigned char Read_Data;
near unsigned char P_SW2;
near unsigned char P_SW6;
#pragma udata

#define Page_Length 8
#define SW2 PORTAbits.RA4
#define SW6 PORTEbits.RE1
#define Bounce_Time 6
#define EE_CMD 0xA0

//***********************************************************
/*    */
/* Main Program    */
/*    */
//***********************************************************

void main(void)
{
ADCON1=0b00000110; // Disable A/D Function
TRISAbits.TRISA4=1; // Set SW2 for input
TRISEbits.TRISE1=1; // Set SW6 for Input
Initialize_Timer2( );
Initialize_I2C_Master( );
OpenLCD( );

if (SW2 & SW6)Debounce=0;
else Debounce = Bounce_Time;

while(1)
{
LCD_Set_Cursor(0,0); // Put LCD Cursor on (0,0)
putrsLCD(LCD_MSG1);
LCD_Set_Cursor(1,0); // Put LCD Cursor on (1,0)
putrsLCD(LCD_MSG2);

P_SW2=P_SW6=0;
Send_Addr=0;

while(1)
{
if (P_SW2)
{
P_SW2=0;
Debounce = Bounce_Time;
LCD_Set_Cursor(0,0); // Put LCD Cursor on (0,0)
putrsLCD(LCD_MSG3);
LCD_Set_Cursor(1,0); // Put LCD Cursor on (0,0)
putrsLCD(LCD_MSG5);

do
{
while (!P_SW2);
P_SW2=0;
LCD_Set_Cursor(1,8);
Send_Data=I2C_Write_Buffer[Send_Addr];
EEPROM_Write(EE_CMD,Send_Addr,Send_Data);
puthexLCD(EE_CMD);
putcLCD(' ');
puthexLCD(Send_Addr);
putcLCD(' ');
puthexLCD(Send_Data);
EEPROM_ACK(EE_CMD);
Send_Addr++;
} while (I2C_Write_Buffer[Send_Addr]!=0x00);
break;
}

if (P_SW6)
{
P_SW6=0;
Debounce = Bounce_Time;
LCD_Set_Cursor(0,0); // Put LCD Cursor on (0,0)
putrsLCD(LCD_MSG4);
LCD_Set_Cursor(1,0); // Put LCD Cursor on (0,0)
putrsLCD(LCD_MSG6);


while(1)
{
if (P_SW6)
{
P_SW6=0;
LCD_Set_Cursor(1,5);
Read_Data = EEPROM_Read(EE_CMD,Send_Addr);
puthexLCD(EE_CMD);
putcLCD(' ');
puthexLCD(Send_Addr);
putcLCD(' ');
puthexLCD(EE_CMD);
putcLCD(' ');
puthexLCD(Read_Data);
Send_Addr++;
}
if (P_SW2) break;
}
if (P_SW2) break;
}
if (P_SW2)
{
P_SW2=0;
     break;
}
}
}
}
//************************************************
//*    #pragma Interrupt Declarations       *
//*    *
//* Function: isr_high_direct                   *
//* - Direct execution to the actual          *
//*    high-priority interrupt code.          *
//************************************************
#pragma code isrhighcode = 0x0008

void isr_high_direct(void)
{
   _asm //begin in-line assembly
   goto isr_high //go to isr_high function
   _endasm //end in-line assembly
}
#pragma code

//************************************************
//* Function: isr_high(void)                   *
//* High priority interrupt for Timer2       *
//************************************************
#pragma interrupt isr_high

void isr_high(void)
{
PIR1bits.TMR2IF=0; // Clear Timer2 interrupt Flag

if (Debounce==0)
{
if (!SW2)
{ P_SW2=1; Debounce =Bounce_Time; }
if (!SW6)
{ P_SW6=1; Debounce =Bounce_Time; }
}
else if (SW2 & SW6)Debounce--;
   else Debounce =Bounce_Time;
}
#pragma code

//***********************************************
//*       Write a Byte to EEPROM
//* - ctrl : Control Byte of EEPROM
//* - addr : Location of EEPROM
//* - data : Data Byte of EEPROM
//***********************************************

void Initialize_Timer2(void)
{

RCONbits.IPEN=1; // Enable Interrupt Priority bit
IPR1bits.TMR2IP=1; // Set Timer2 for High Priority
INTCONbits.GIEH=1; // Enable High Priority Interrupt

OpenTimer2 (TIMER_INT_ON // Turn On the Timer2 with Interrupt
      & T2_PS_1_4 // (4Mhz/4) [4*10*(99+1)] = 4mS */
      & T2_POST_1_10);

PR2 = 99;
}

//***********************************************
//*       Write a Byte to EEPROM             *
//* - ctrl : Control Byte of EEPROM *
//* - addr : Location of EEPROM *
//* - data : Data Byte of EEPROM *
//***********************************************
void EEPROM_Write(unsigned char ctrl,unsigned char addr,unsigned char data)
{
IdleI2C();          // ensure module is idle
    StartI2C(); // Start condition
I2C_Done(); // Wait Start condition completed and clear SSPIF flag

WriteI2C(ctrl); // Write Control+Write to EEPROM & Check BF flag
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done(); // Clear SSPIF flag

WriteI2C(addr); // Write Address to EEPROM
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done();

WriteI2C(data); // Write Data to EEPROM
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done();

StopI2C(); // Stop condition
I2C_Done(); // Wait the Stop condition completed
}

//***********************************************
//*       Pae Write to EEPROM
//*
//* - ctrl : Control Byte of EEPROM
//* - addr : Location of EEPROM
//* - length : Write counter
//* - *dptr : RAM point --> EEPROM
//*
//***********************************************
void EE_Page_Write(unsigned char ctrl,unsigned char addr,unsigned char length,unsigned char *dptr)
{
IdleI2C();          // ensure module is idle
    StartI2C(); // Start condition
I2C_Done(); // Wait Start condition completed

WriteI2C(ctrl); // Write Control+Write to EEPROM & Check BF flag
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done(); // Clear SSPIF flag

WriteI2C(addr); // Write Address to EEPROM
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done();

while (length!=0) // Check write completed ?
{
WriteI2C(*dptr); // Write data to EEPROM
while(SSPCON2bits.ACKSTAT); // wait until received the Acknowledge from EEPROM
I2C_Done();
dptr++; // Point to next byte
length--;
}

StopI2C(); // Stop condition
I2C_Done(); // Wait the Stop condition completed
}

//***********************************************
//*       EEPROM Acknowledge Polling       *
//* --  The routine will polling the ACK *
//*    response from EEPROM    *
//* --  ACK=0 return *
//*    --  ACK=1 send Restart & loop check *
//***********************************************
void EEPROM_ACK(unsigned char ctrl)
{
unsigned char i;

IdleI2C();          // ensure module is idle
    StartI2C(); // Start condition
I2C_Done(); // Wait Start condition completed

WriteI2C(ctrl); // Write Control to EEPROM (WRITE)
I2C_Done(); // Clear SSPIF flag

while (SSPCON2bits.ACKSTAT) // test for Acknowledge from EEPROM
{
for (i=0;i<100;i++); // Delay for next Repet-Start

      RestartI2C();               // initiate Repet-Start condition
I2C_Done();    // Wait Repet-Start condition completed

WriteI2C(ctrl); // Write Control to EEPROM (WRITE)
I2C_Done(); // Clear SSPIF flag
}
StopI2C();                   // send STOP condition
I2C_Done(); // wait until stop condition is over
}

//***********************************************
//* Random Read a Byte from EEPROM          *
//* - ctrl : Control Byte of EEPROM (Write) *
//*    (Ctrl +1 ) : Read Command *
//* - addr : Address Byte of EEPROM *
//* - Return : Read Data from EEPROM *
//***********************************************
unsigned char EEPROM_Read(unsigned char ctrl,unsigned char addr)
{
unsigned char f;

IdleI2C();          // ensure module is idle
    StartI2C(); // Start condition
I2C_Done(); // Wait Start condition completed

WriteI2C(ctrl); // Write Control to EEPROM
while(SSPCON2bits.ACKSTAT);    // test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

WriteI2C(addr); // Write Address to EEPROM
while(SSPCON2bits.ACKSTAT);    // test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

   RestartI2C();               // initiate Restart condition
I2C_Done();

WriteI2C(ctrl+1); // Write Control to EEPROM
while(SSPCON2bits.ACKSTAT);    // test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

f=ReadI2C(); // Enable I2C Receiver & wait BF=1 until received data
I2C_Done(); // Clear SSPIF flag

NotAckI2C(); // Genarate Non_Acknowledge to EEPROM
I2C_Done();

StopI2C();                   // send STOP condition
I2C_Done(); // wait until stop condition is over

return(f); // Return Data from EEPROM
}

//***********************************************
//*       Sequential Read from EEPROM
//*
//* - ctrl : Control Byte of EEPROM
//* - addr : Location of EEPROM
//* - length : Read counter
//* - *dptr : Store EEPROM data to RAM
//*
//***********************************************
void EE_SEQU_Read(unsigned char ctrl,unsigned char addr,unsigned char length,unsigned char *dptr)
{
IdleI2C();          // ensure module is idle
    StartI2C(); // Start condition
I2C_Done(); // Wait Start condition completed

WriteI2C(ctrl); // Write Control to EEPROM
while(SSPCON2bits.ACKSTAT);    // test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

WriteI2C(addr); // Write Address to EEPROM
while(SSPCON2bits.ACKSTAT);    // test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

   RestartI2C();               // initiate Restart condition
I2C_Done();

WriteI2C(ctrl+1); // Write Control to EEPROM
while(SSPCON2bits.ACKSTAT);    // Test for ACK condition, if received
I2C_Done(); // Clear SSPIF flag

while (length!=0)
{
*dptr=ReadI2C(); // Enable I2C Receiver & Store EEPROM data to Point buffer
I2C_Done();
dptr++;
length--;

if (length==0) NotAckI2C();
else AckI2C(); // Continue read next data, send a acknowledge to EEPROM

I2C_Done();
}

StopI2C();                   // send STOP condition
I2C_Done(); // wait until stop condition is over
}

//***********************************************
//* Check I2C action that is completed       *
//***********************************************
void I2C_Done(void)
{
while (!PIR1bits.SSPIF); // Completed the action when the SSPIF is Hi.
PIR1bits.SSPIF=0;    // Clear SSPIF
}

//************************************************
//* Initial I2C Master Mode with 7 bits Address  *
//* Clock Speed : 100KHz @4MHz    *
//************************************************
void Initialize_I2C_Master(void)
{
OpenI2C(MASTER,SLEW_ON);
SSPADD= 9;
}

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