一个基于DSP2812的DS1390串行EEPROM的驱动源代码
一个基于DSP2812的DS1390串行EEPROM的驱动源代码
前段时间写的一个EEPROM的程序，已经测试通过。
常见的EEPROM总线结构共有三种：I2C，Microwire,SPI.。
DS1390就是一个很常见的串行EEPROM芯片。区别于不同的型号和厂家，引脚定义似稍有不同，但是大致类似的，需要注意的是CS不能直接拉高，哪怕系统里只有一个芯片，因为CS对时序的控制还有很多作用。其次，注意ORG将决定存贮器的组织方式，分为8X和16X两种。PE在有些厂家的芯片上没有（比如Fairchild的芯片），即为NC或NU,Microchip 的产品需要上拉到VCC。最后要注意的是CS最好加个下拉电阻。具体细节可以参照各型号的数据手册，另外也有些应用笔记可以参考，只要读懂一个系列uC的代码，操作顺序就是大同小异的，可以举一反三
以下就是源代码的部分函数：
#include <stdlib.h>
#include "DSP28_Device.h"
unsigned int uiData=0; // 16-bit Data word
/** P R O T O T Y P E S ********************************************/
void McEEP_Init(void); // Init. function
void McEEP_Bitout(void); // Bit output function
void McEEP_Bitin(void); // Bit input function
void McEEP_Byteout(void); // Byte output function
void McEEP_Bytein(void); // Byte input function
void McEEP_SendCommand(void); // Command output function
void McEEP_Poll(void); // Ready/Busy polling function
void McEEP_Ewen(void); // Erase/Write Enable function
void McEEP_Ewds(void); // Erase/Write Disable function
void McEEP_WriteByte(unsigned char); // 8-bit Write function
void McEEP_WriteWord(unsigned int); // 16-bit Write function
void McEEP_WriteAllWord(unsigned int); // Write all cells with same value
unsigned char McEEP_ReadByte(void); // 8-bit Read function
unsigned int McEEP_ReadWord(void); // 16-bit Read function
void McEEP_EraseByte(void); // 8-bit Erase function
void McEEP_EraseWord(void); // 16-bit Erase function
void McEEP_EraseAll(void); // Erase all cells
void Set_Delay(unsigned int); //delay time
void Delay_10ms(void); //delay time
/********************************************************************
* Function: void EEP_Bitout(void)
*
* Description: This function outputs the MSb of buffer to the
* serial EEPROM device.
*******************************************************************/
void McEEP_Bitout(void)
{
// unsigned char i=0;
if (ucBuffer & 0x80) // Check if next bit is a 1
{ // Get MSb
GpioDataRegs.GPFDAT.bit.GPIOF0=1; // If so, send a 1
}
else // Otherwise
{
GpioDataRegs.GPFDAT.bit.GPIOF0=0; // Send a 0
}
Delay_10ms(); // Avoid violating Tckh,may be more
GpioDataRegs.GPFDAT.bit.GPIOF2=1; // Bring SCK high to latch data
Delay_10ms(); // Avoid violating Tckh,may be more
GpioDataRegs.GPFDAT.bit.GPIOF2=0; // Bring SCK low for next bit
Delay_10ms(); // Avoid violating Tckh,may be more
} //end (void)
/********************************************************************
* Function: void EEP_Bitin(void)
*
* Description: This function inputs a bit from the serial EEPROM
* device and stores it in the LSb of buffer.
*******************************************************************/
void McEEP_Bitin(void)
{
// unsigned char i=0;
ucBuffer &= 0xFE; // Assume next bit(low bit) will be 0
GpioDataRegs.GPFDAT.bit.GPIOF2=1; // Bring SCK to latch data
Delay_10ms(); // Avoid violating Tckh
GpioDataRegs.GPFDAT.bit.GPIOF2=0; // Bring SCK low, and read at low jump
Delay_10ms();
if (GpioDataRegs.GPFDAT.bit.GPIOF1==1) // Check if DI is high(1)
{
ucBuffer |= 0x01; // If high, set next bit
} // else remain the LSb as 0
} //end McEEP_Bitin(void)
/********************************************************************
* Function: void EEP_Byteout(void)
*
* Description: This function outputs the byte specified in
* buffer to the serial EEPROM device.
*******************************************************************/
void McEEP_Byteout(void)
{
unsigned char i; // Loop counter
for (i = 0; i < 8; i++) // Loop through each bit
{
McEEP_Bitout(); // Output bit
ucBuffer = ucBuffer << 1; // Rotate left for next bit
}
} // end McEEP_Byteout(void)
/********************************************************************
* Function: void EEP_Bytein(void)
*
* Description: This function inputs a byte from the serial
* EEPROM device and stores it in buffer.
*******************************************************************/
void McEEP_Bytein(void)
{
unsigned char i; // Loop counter
ucBuffer = 0;
for (i = 0; i < 8; i++) // Loop through each bit
{
ucBuffer = ucBuffer << 1; // Rotate left for next bit
McEEP_Bitin(); // Input bit
}
} // end McEEP_Bytein(void)
/********************************************************************
* Function: void EEP_SendCommand(void)
*
* Description: This function sends the Start bit and opcode
* specified in the MSb's of ucCommand, as well as
* the required number of uiAddress or dummy bits,
* to the serial EEPROM device.
*******************************************************************/
void McEEP_SendCommand(void)
{
static unsigned char i; // Loop counter
static unsigned int cmd_addr; // Variable for ucCommand & uiAddress
static unsigned int temp; // Temp. variable
cmd_addr = uiAddress; // Copy uiAddress to cmd_addr;
// First, align uiAddress bits to be combined with ucCommand
for (i = 0; i < (16-NUMBITS); i++) // Skip through unused addr. bits
{
cmd_addr = cmd_addr << 1; // Rotate left to skip bit
}
// Next, combine ucCommand into uiAddress word
cmd_addr &= 0x1FFF; // Mask off upper 3 bits
temp = ucCommand; // Copy ucCommand value to temp
cmd_addr |= (temp<<8); // Combine uiAddress & ucCommand
// Finally, output entire ucCommand to device
for (i = 0; i < NUMBITS; i++) // Loop through each bit
{
ucBuffer = (char)(cmd_addr >> 8); // Copy uiAddress MSB to buffer
McEEP_Bitout(); // Output next bit
cmd_addr = cmd_addr << 1; // Rotate left for next bit
}
} // end McEEP_SendCommand(void)
/********************************************************************
* Function: void EEP_Poll(void)
*
* Description: This function brings CS high to initiate the
* Ready/Busy polling feature. DO is then continuously
* polled to see when it goes high, thus indicating
* that the write cycle has completed.
*******************************************************************/
void McEEP_Poll(void)
{
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Set CS high
Delay_10ms(); // Avoid violating Tsv
while (GpioDataRegs.GPFDAT.bit.GPIOF1==0) {}; // Wait until DI is high
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Bring CS low
} // end McEEP_Poll(void)
/********************************************************************
* Function: void EEP_Ewen(void)
*
* Description: This function sends an EWEN ucCommand to the device.
* Once this ucCommand has been given, writing to the
* device array will be enabled, and will remain as
* such until an EWDS ucCommand is given or power is
* removed from the device.
*******************************************************************/
void McEEP_Ewen(void)
{
ucCommand=EWEN_CMD; // Load EWEN ucCommand value
uiAddress=0; // Clear uiAddress word
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms();
} // end Ewen(void)
/********************************************************************
* Function: void EEP_Ewds(void)
*
* Description: This function sends an EWDS ucCommand to the device.
* It is good practice to always send this ucCommand
* after completing a write, so as to avoid the
* corruption of data stored in the device.
*******************************************************************/
void McEEP_Ewds(void)
{
ucCommand=EWDS_CMD; // Load EWDS ucCommand value
uiAddress=0; // Clear uiAddress word
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
} // end Ewds(void)
/********************************************************************
* Function: void EEP_WriteByte(unsigned char data)
*
* Description: This function writes the 8-bit value stored in
* data to the serial EEPROM device, at the location
* specified by uiAddress.
*******************************************************************/
void McEEP_WriteByte(unsigned char data)
{
ucCommand = WRITE_CMD; // Load WRITE ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
ucBuffer = data; // Copy data to buffer
McEEP_Byteout(); // Output byte
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms();
McEEP_Poll(); // Begin ready/busy polling
} // end WriteX8(unsigned char data)
/********************************************************************
* Function: void EEP_WriteWord(unsigned int data)
*
* Description: This function writes the 16-bit value stored in
* data to the serial EEPROM device, at the location
* specified by uiAddress.
*******************************************************************/
void McEEP_WriteWord(unsigned int data)
{
ucCommand = WRITE_CMD; // Load WRITE ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
ucBuffer = (char)(data >> 8); // Copy data MSB to buffer
McEEP_Byteout(); // Output byte,发高8位数据
ucBuffer = (char)data; // Copy data LSB to buffer
McEEP_Byteout(); // Output byte,发低8位数据
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms(); // Delay for Tcs low
McEEP_Poll(); // Begin ready/busy polling
} // end WriteX16(unsigned int data)
/********************************************************************
* Function: unsigned char EEP_ReadByte(void)
*
* Description: This function reads an 8-bit value from the
* serial EEPROM device, from the location
* specified by uiAddress, returns it.
*******************************************************************/
unsigned char McEEP_ReadByte(void)
{
ucCommand = READ_CMD; // Load READ ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
McEEP_Bytein(); // Input byte from device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
return ucBuffer; // Return value
} // end ReadX8(void)
/********************************************************************
* Function: unsigned int EEP_ReadWord(void)
*
* Description: This function reads a 16-bit value from the
* serial EEPROM device, from the location
* specified by uiAddress, returns it.
*******************************************************************/
unsigned int McEEP_ReadWord(void)
{
unsigned int retval; // Return value variable
ucCommand = READ_CMD; // Load READ ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
McEEP_Bytein(); // Input byte from device
retval = ucBuffer; // Copy byte to retval MSB
McEEP_Bytein(); // Input byte from device
retval = (retval << 8) | ucBuffer; // Copy byte to retval LSB
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms(); // Avoid violating Tckh,may be more
ucBuffer = 0;
return retval; // Return value
} // end ReadX16(void)
/********************************************************************
* Function: void McEEP_EraseByte();
*
* Description: This function erase a 8-bit value from the
* serial EEPROM device, from the location
* specified by uiAddress.
*******************************************************************/
void McEEP_EraseByte()
{
ucCommand = ERASE_CMD; // Load ERASE ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms(); // Avoid violating timming
McEEP_Poll();
}
/********************************************************************
* Function: void McEEP_EraseWord(void)
*
* Description: This function erase a 16-bit value from the
* serial EEPROM device, from the location
* specified by uiAddress.
*******************************************************************/
void McEEP_EraseWord(void)
{
ucCommand = ERASE_CMD; // Load ERASE ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms(); // Avoid violating timming
McEEP_Poll(); // Begain Ready/Busy polling
}
/********************************************************************
* Function: void McEEP_EraseAll(void)
*
* Description: This function erase all cells' value from the
* serial EEPROM device.
*******************************************************************/
void McEEP_EraseAll(void)
{
ucCommand = ERAL_CMD; // Load ERAL ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Selcet
Delay_10ms(); // Avoid violating Tc
McEEP_Poll(); // Begain Ready/Busy polling
}
/********************************************************************
* Function: void McEEP_WriteAllWord(unsigned int)
*
* Description: This function write all cells with same value .
*
*******************************************************************/
void McEEP_WriteAllWord(unsigned int data)
{
ucCommand = WRAL_CMD; // Load WRITE ucCommand value
GpioDataRegs.GPFDAT.bit.GPIOF3=1; // Enable Chip Select
McEEP_SendCommand(); // Output ucCommand to device
ucBuffer = (char)(data >> 8); // Copy data MSB to buffer
McEEP_Byteout(); // Output byte
ucBuffer = (char)data; // Copy data LSB to buffer
McEEP_Byteout(); // Output byte
GpioDataRegs.GPFDAT.bit.GPIOF3=0; // Disable Chip Select
Delay_10ms(); // Delay for Tcs low
McEEP_Poll(); // Begin ready/busy polling
} |
楼主
标题置顶
标题高亮
