?? _iic.c
字號:
/*
* Copyright 2004 by Texas Instruments Incorporated.
* All rights reserved. Property of Texas Instruments Incorporated.
* Restricted rights to use, duplicate or disclose this code are
* granted through contract.
*
*/
/* August 2004 */
/********************************************************************/
/* _iic.c file */
/********************************************************************/
#include "_iic.h"
#define I2CDELAY(iterations) { \
volatile Int j; \
for(j = 0; j < iterations; j ++); \
}
#define DELAY_TIME 1000
static const I2C_Config EVM642VIDEOIIC_WriteConfig = {
0, /* master mode, i2coar; */
0, /* no interrupt, i2cimr; */
(20-5), /* scl low time, i2cclkl; */
(20-5), /* scl high time,i2cclkh; */
1, /* configure later, i2ccnt;*/
0, /* configure later, i2csar;*/
0x46a0, /* master tx mode, */
/* i2c runs free, */
/* 8-bit data + NACK */
/* repeat mode */
(75-1), /* 4MHz clock, i2cpsc */
};
static const I2C_Config EVM642VIDEOIIC_ReadConfig = {
0, /* master mode, i2coar; */
0, /* no interrupt, i2cimr; */
(20-5), /* scl low time, i2cclkl; */
(20-5), /* scl high time,i2cclkh; */
1, /* configure later, i2ccnt;*/
0, /* configure later, i2csar;*/
0x44a0, /* master rx mode, */
/* i2c runs free, */
/* 8-bit data + ACK */
/* repeat mode */
(75-1), /* 4MHz clock, i2cpsc */
};
/*
* ======== _IIC_write ========
* This function performs write operation via I2C bus.
*/
void _IIC_write(I2C_Handle hI2C,
Uint8 devAddress,
Uint32 subAddress,
Uint8 *data,
Uint16 numBytes
)
{
Int i;
I2C_Config prevIICConfig;
/* make sure handle is valid */
if(hI2C == INV) {
return;
}
/* Wait until bus is free */
while (I2C_bb(hI2C));
/* save old settings */
I2C_getConfig(hI2C, &prevIICConfig);
/* set I2C mode register */
I2C_RSETH(hI2C, I2CMDR, EVM642VIDEOIIC_WriteConfig.i2cmdr);
/* set I2C imr register */
I2C_RSETH(hI2C, I2CIMR, EVM642VIDEOIIC_WriteConfig.i2cimr);
/* configure the I2C slave address register */
I2C_RSETH(hI2C, I2CSAR, devAddress);
/* set I2C count register */
I2C_RSETH(hI2C, I2CCNT, numBytes + 1);
/* write the sub address */
I2C_writeByte(hI2C, subAddress);
/* Generate start condition */
I2C_start(hI2C);
I2CDELAY(DELAY_TIME);
/* write the data */
for(i = 0; i < numBytes; i ++) {
while(!I2C_xrdy(hI2C));
I2C_writeByte(hI2C, *data ++);
I2CDELAY(DELAY_TIME);
}
/* Generate stop condition */
I2C_sendStop(hI2C);
I2CDELAY(DELAY_TIME);
/* Wait until bus is free */
while (I2C_bb(hI2C));
I2CDELAY(DELAY_TIME);
/* now restore the previous I2C settings */
I2C_config(hI2C, &prevIICConfig);
I2CDELAY(DELAY_TIME);
}
void _IIC_read(I2C_Handle hI2C,
Uint8 devAddress,
Uint32 subAddress,
Uint8 *data,
Uint16 numBytes
)
{
Int i;
I2C_Config prevIICConfig;
/* make sure handle is valid */
if(hI2C == INV) {
return;
}
/* Wait until bus is free */
while (I2C_bb(hI2C));
/* save old settings */
I2C_getConfig(hI2C, &prevIICConfig);
/* set I2C mode register */
I2C_RSETH(hI2C, I2CMDR, EVM642VIDEOIIC_WriteConfig.i2cmdr);
/* set I2C imr register */
I2C_RSETH(hI2C, I2CIMR, EVM642VIDEOIIC_WriteConfig.i2cimr);
/* configure the I2C slave address register */
I2C_RSETH(hI2C, I2CSAR, devAddress);
/* set I2C count register */
I2C_RSETH(hI2C, I2CCNT, 1);
/* write the sub address */
I2C_writeByte(hI2C, subAddress);
/* Generate start condition */
I2C_start(hI2C);
I2CDELAY(DELAY_TIME);
/* waiting for sub-address to be transmitted */
while(!I2C_xrdy(hI2C));
/* now enter the master receiver mode */
I2C_RSETH(hI2C, I2CMDR, EVM642VIDEOIIC_ReadConfig.i2cmdr);
/* set I2C count register */
I2C_RSETH(hI2C, I2CCNT, numBytes);
/* clear the DRR register */
I2C_readByte(hI2C);
/* Generate start condition */
I2C_start(hI2C);
I2CDELAY(DELAY_TIME);
/* read the data */
for(i = 0; i < numBytes; i ++) {
while(!I2C_rrdy(hI2C));
*data++ = I2C_readByte(hI2C);
I2CDELAY(DELAY_TIME);
}
/* Generate stop condition */
I2C_sendStop(hI2C);
I2CDELAY(DELAY_TIME);
/* Wait until bus is free */
while (I2C_bb(hI2C));
I2CDELAY(DELAY_TIME);
/* now restore the previous I2C settings */
I2C_config(hI2C, &prevIICConfig);
I2CDELAY(DELAY_TIME);
}
?? 快捷鍵說明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -