先贴上程序
void SkI2cInit (void)
{
// The I2C0 peripheral must be enabled before use.
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
GPIOPinConfigure(GPIO_PB2_I2C0SCL);
GPIOPinConfigure(GPIO_PB3_I2C0SDA);
// Select the I2C function for these pins. This function will also
// configure the GPIO pins pins for I2C operation, setting them to
// open-drain operation with weak pull-ups. Consult the data sheet
// to see which functions are allocated per pin.
ROM_GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_2 | GPIO_PIN_3);
// Enable and initialize the I2C0 master module. Use the system clock for
// the I2C0 module. The last parameter sets the I2C data transfer rate.
// If false the data rate is set to 100kbps and if true the data rate will
// be set to 400kbps. For this example we will use a data rate of 100kbps.
ROM_I2CMasterInitExpClk(I2C0_MASTER_BASE, ROM_SysCtlClockGet(), false);
}
void I2cWriteByte(unsigned char deviceID,unsigned char offset,unsigned value)
{
ROM_I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, deviceID, false);
ROM_I2CMasterDataPut(I2C0_MASTER_BASE, offset);
ROM_I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);
while(ROM_I2CMasterBusy(I2C0_MASTER_BASE))
{
}
ROM_I2CMasterDataPut(I2C0_MASTER_BASE, value);
ROM_I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);
while(ROM_I2CMasterBusy(I2C0_MASTER_BASE))
{
}
}
unsigned char I2cReadByte(unsigned char deviceID,unsigned char offset)
{
unsigned char value;
ROM_I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, deviceID, false);
//This function will set the address that the I2C Master will place on the bus when initiating a
//transaction. When the bReceive parameter is set to true, the address will indicate that the
//I2C Master is initiating a read from the slave; otherwise the address will indicate that the I2C
//Master is initiating a write to the slave.
ROM_I2CMasterDataPut(I2C0_MASTER_BASE, offset);//Transmits a byte from the I2C Master
ROM_I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);//Controls the state of the I2C Master module.
while(ROM_I2CMasterBusy(I2C0_MASTER_BASE))//Indicates whether or not the I2C Master is not-busy.
{
}
ROM_I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, deviceID, true);
ROM_I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE);
while(ROM_I2CMasterBusy(I2C0_MASTER_BASE))
{
}
value=ROM_I2CMasterDataGet(I2C0_MASTER_BASE);//Receives a byte that has been sent to the I2C Master.
return (value);
}
//*****************************************************************************
//
// Print "Hello world!" to the UART on the Stellaris evaluation board.
//
//*****************************************************************************
int
main(void)
{
unsigned char buffer=0;
//
// Set the clocking to run directly from the crystal.
//
ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_16MHZ);
//
// Initialize the UART.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
GPIOPinConfigure(GPIO_PA0_U0RX);
GPIOPinConfigure(GPIO_PA1_U0TX);
ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
UARTStdioInit(0);
SkI2cInit();
// Hello!
//
UARTprintf("\033[2JHello World!\n");
while(1)
{
//I2cWriteByte(0x64>>1,0x08,0x23);
buffer=I2cReadByte(0x64>>1,0x08);
UARTprintf("Received:%02x\n",buffer);
}
}
以下是此芯片的I2C时序
现在我单独调用I2cReadByte（）；通过串口打印UARTprintf（）能读到该芯片的ID寄存器以及其他默认不为0的寄存器的值；
但是我先用I2cWriteByte（）；写某个寄存器，再用I2cReadByte（）；读出这个寄存器的值发现读不到这个寄存器的值，很奇怪，请大家帮我分析分析
另外Stellaris® Peripheral Driver Library USER’S GUIDE 文档中 “I2CMasterControl（）” 此函数的用法大家有详细说明吗？以下命令：
I2C_MASTER_CMD_SINGLE_SEND
I2C_MASTER_CMD_SINGLE_RECEIVE
I2C_MASTER_CMD_BURST_SEND_START
I2C_MASTER_CMD_BURST_SEND_CONT
I2C_MASTER_CMD_BURST_SEND_FINISH
I2C_MASTER_CMD_BURST_SEND_ERROR_STOP
I2C_MASTER_CMD_BURST_RECEIVE_START
I2C_MASTER_CMD_BURST_RECEIVE_CONT
I2C_MASTER_CMD_BURST_RECEIVE_FINISH
I2C_MASTER_CMD_BURST_RECEIVE_ERROR_STOP
I2C_MASTER_CMD_QUICK_COMMAND
I2C_MASTER_CMD_HS_MASTER_CODE_SEND
都是怎么用的？
非常感谢！
