28335调试I2C问题

只看该作者 · 2015-4-20 19:10

在调试的过程中遇到一些问题，我程序写的是只发一帧，循环发。一旦写进数据寄存器我就产生开始条件，进行传输。等待到结束标志信号后，我就重新发。示波器显示的scl为9个时钟，但是无论我数据传的是什么，sda显示的都不变，不知道为什么啊。主机是DSP，从机的地址为0x90;
选的是七位地址模式（好像是利用七位地址模式不行）还有就是例程中在发送时，先往I2CDXR发送两字节地址，再接着发送四字节数据后才配置I2CMDR。个人理解是否应一个一个的发数据，在每一帧发送数据的时候找好对应的标志位，因为发送寄存器是只有一个的，一次写那么多，怎么发呢？我把我写的程序放上去，麻烦知道看看，不要说给你个官方，因为我看了例程，没看懂。

#include "DSP28x_Project.h"    // Device Headerfile and Examples Include File

// Note: I2C Macros used in this example can be found in the
// DSP2833x_I2C_defines.h file

// Prototype statements for functions found within this file.
void I2CA_Init(void);
void I2CA_WriteData(Uint16 data);//写数据

#define I2C_SLAVE_ADDR       0x91//从地址
#define I2C_NUMBYTES       4//传输字节数
#define I2C_EEPROM_HIGH_ADDR  0x00//高位地址
#define I2C_EEPROM_LOW_ADDR 0x30//低位地址

void main(void)
{

Uint16 i;

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();
// Setup only the GP I/O only for I2C functionality
InitI2CGpio();

// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;

// Initialize PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2833x_PieCtrl.c file.
InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_PieVect.c.
InitPieVectTable();

// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
EALLOW; // This is needed to write to EALLOW protected registers
  // PieVectTable.I2CINT1A = &i2c_int1a_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
I2CA_Init();

// Enable interrupts required for this example

// Enable I2C interrupt 1 in the PIE: Group 8 interrupt 1
PieCtrlRegs.PIEIER8.bit.INTx1 = 1;

// Enable CPU INT8 which is connected to PIE group 8
// IER |= M_INT8;
EINT;
      I2CA_WriteData(0x0000);
} // end of main

void I2CA_Init(void)
{
// Initialize I2C
I2caRegs.I2CMDR.bit.IRS = 0;
I2caRegs.I2CSAR = 0x0090; // Slave address - EEPROM control code

#if (CPU_FRQ_150MHZ)          // Default - For 150MHz SYSCLKOUT
      I2caRegs.I2CPSC.all = 14; // Prescaler - need 7-12 Mhz on module clk (150/15 = 10MHz)
#endif
#if (CPU_FRQ_100MHZ)          // For 100 MHz SYSCLKOUT
   I2caRegs.I2CPSC.all = 9;       // Prescaler - need 7-12 Mhz on module clk (100/10 = 10MHz)
#endif

I2caRegs.I2CCLKL = 45; // NOTE: must be non zero
I2caRegs.I2CCLKH = 45; // NOTE: must be non zero
I2caRegs.I2CIER.all = 0x24; // Enable SCD & ARDY interrupts

I2caRegs.I2CMDR.all = 0x0020; // Take I2C out of reset

   // Stop I2C when suspended

// I2caRegs.I2CSTR.bit.ARDY=1;
// I2caRegs.I2CFFTX.all = 0x6000; // Enable FIFO mode and TXFIFO
// I2caRegs.I2CFFRX.all = 0x2040; // Enable RXFIFO, clear RXFFINT,

}

void I2CA_WriteData(Uint16 data)
{
  char Busy_flag;
Busy_flag = I2caRegs.I2CSTR.bit.BB;//判断总线是否忙
if(!Busy_flag)
{
      //  I2caRegs.I2CSAR = 0xF0;
         I2caRegs.I2CSAR = 0x90;
            I2caRegs.I2CCNT = 1;
      I2caRegs.I2CDXR = data;

   while(I2caRegs.I2CSTR.bit.XRDY==0)
   I2caRegs.I2CMDR.all = 0x6E20;
   //  while(I2caRegs.I2CSTR.bit.XRDY==1)
   // I2caRegs.I2CDXR = data;

      if(I2caRegs.I2CSTR.bit.SCD==0)
for(;;);
      if(I2caRegs.I2CSTR.bit.SCD==1)
         I2CA_WriteData(0x00);
}

}