www.pudn.com > Grayscale.rar > iic.c

/***********************************************************/ 
/*  Copyright 2003 by SEED Incorporated.				   */ 
/*  All rights reserved. Property of SEED Incorporated.    */  
/*  											           */ 
/***********************************************************/ 
#include "iic.h"       
 
#define I2CDELAY(iterations)  {      \ 
    volatile Int j;                  \ 
    for(j = 0; j < iterations; j ++); \ 
}    
#define DELAY_TIME 0x4000 
/*SEEDDM642的IIC的设置结构*/ 
I2C_Config SEEDDM642IIC_Configt = { 
    0,  /* master mode,  i2coar;采用主模式   */ 
    0,  /* no interrupt, i2cimr;只写，不读，采用无中断方式*/ 
    (20-5), /* scl low time, i2cclkl;  */ 
    (20-5), /* scl high time,i2cclkh;  */ 
    2,  /* configure later, i2ccnt;*/ 
    0,  /* configure later, i2csar;*/ 
    0x4620, /* master tx mode,     */ 
            /* i2c runs free,      */ 
            /* 8-bit data + NACK   */ 
            /* no repeat mode      */ 
    (75-1), /* 2MHz clock, i2cpsc  */ 
}; 
 
I2C_Config SEEDDM642IIC_Configr = { 
    0,  /* master mode,  i2coar;采用主模式   */ 
    0,  /* no interrupt, i2cimr;只写，不读，采用无中断方式*/ 
    (20-5), /* scl low time, i2cclkl;  */ 
    (20-5), /* scl high time,i2cclkh;  */ 
    1,  /* configure later, i2ccnt;*/ 
    0,  /* configure later, i2csar;*/ 
    0x4420, /* master tx mode,     */ 
            /* i2c runs free,      */ 
            /* 8-bit data + NACK   */ 
            /* no repeat mode      */ 
    (75-1), /* 2MHz clock, i2cpsc  */ 
}; 
 
 
/* 
 * ======== _IIC_write ======== 
 * This function performs write operation via I2C bus. 
 */ 
/* Spin in a delay loop for delay iterations */ 
void EVMDM642_wait(Uint32 delay) 
{ 
    volatile Uint32 i, n; 
     
    n = 0; 
    for (i = 0; i < delay; i++) 
    { 
        n = n + 1; 
    } 
} 
 
/* Spin in a delay loop for delay microseconds */ 
void EVMDM642_waitusec(Uint32 delay) 
{ 
    EVMDM642_wait(delay * 21); 
} 
 
void _IIC_write(I2C_Handle hI2C, 
              Uint8 devAddress, 
              Uint32  subAddress, 
              Uint8 data 
              ) 
{              
    I2C_Config prevI2CCfg; 
     
    /* Wait until bus is free */ 
    while (I2C_bb(hI2C)); 
     
    /* Save old settings */ 
    I2C_getConfig(hI2C, &prevI2CCfg); 
     
    /* Restore settings for AIC23 */ 
    SEEDDM642IIC_Configt.i2csar = devAddress; 
    I2C_config(hI2C, &SEEDDM642IIC_Configt); 
 
    /* Submit the MSB for transmit */ 
    I2C_RSETH(hI2C, I2CDXR, (subAddress) & 0xff); 
     
    /* Generate start condition, starts transmission */ 
    I2C_start(hI2C); 
     
    /* Wait until MSB transmit is done */ 
    while(!I2C_xrdy(hI2C)); 
 
    /* Submit the LSB for transmit */  
    I2C_RSETH(hI2C, I2CDXR,data);     
 //   EVMDM642_waitusec(350); 
     
    /* Generate stop condition */ 
    I2C_sendStop(hI2C);   
 
    /* Wait until bus is free */ 
    while (I2C_bb(hI2C)); 
             
    EVMDM642_waitusec(350); 
 
    /* Reconfigure I2C with old settings */ 
    I2C_config(hI2C, &prevI2CCfg);               
}      
 
/* 
 * ======== _IIC_read ======== 
 * This function performs read from operation via I2C bus. 
 */ 
 
void _IIC_read(I2C_Handle hI2C, 
              Uint8 devAddress, 
              Uint32  subAddress, 
              Uint8 *data 
              ) 
{ 
    I2C_Config prevI2CCfg; 
     
    /* Wait until bus is free */ 
    while (I2C_bb(hI2C)); 
     
    /* Save old settings */ 
    I2C_getConfig(hI2C, &prevI2CCfg); 
     
    /* Restore settings for AIC23 */ 
    SEEDDM642IIC_Configt.i2csar = devAddress; 
    I2C_config(hI2C, &SEEDDM642IIC_Configt); 
 
    /* Submit the MSB for transmit */ 
    I2C_RSETH(hI2C, I2CDXR, (subAddress) & 0xff); 
     
    /* Generate start condition, starts transmission */ 
    I2C_start(hI2C); 
     
    /* Wait until MSB transmit is done */ 
    while(!I2C_xrdy(hI2C)); 
         
    /* Generate stop condition */ 
    I2C_sendStop(hI2C);   
	EVMDM642_waitusec(20); 
 
    /* Reconfigure I2C with old settings */ 
    I2C_config(hI2C, &prevI2CCfg); 
  	I2C_getConfig(hI2C, &prevI2CCfg); 
    /*从发送到接收需一段时间转换*/ 
    EVMDM642_waitusec(0x200); 
    /* Restore settings for AIC23 */ 
    SEEDDM642IIC_Configr.i2csar = devAddress; 
    I2C_config(hI2C, &SEEDDM642IIC_Configr); 
    /* Generate start condition, starts transmission */ 
    I2C_start(hI2C); 
    while(I2C_FGETH(hI2C,I2CSTR,ARDY)); 
    /* Wait until MSB transmit is done */ 
    while(!I2C_rrdy(hI2C)); 
 
    /* Submit the MSB for transmit */ 
    *data = I2C_RGETH(hI2C, I2CDRR); 
         
    /* Generate stop condition */ 
    I2C_sendStop(hI2C);   
     
    /* Wait until bus is free */ 
    while (I2C_bb(hI2C));  
 
    /* Short delay for AIC23 to accept command */         
    EVMDM642_waitusec(20); 
 
    /* Reconfigure I2C with old settings */ 
    I2C_config(hI2C, &prevI2CCfg);           
}