// TI File $Revision: /main/4 $
// Checkin $Date: December 17, 2009 14:34:43 $
//###########################################################################
//
// FILE: Example_2802xI2c_eeprom.c
//
// TITLE: DSP2802x I2C EEPROM Example
//
// ASSUMPTIONS:
//
// This program requires the DSP2802x header files.
//
// This program requires an external I2C EEPROM connected to
// the I2C bus at address 0x50.
//
// As supplied, this project is configured for "boot to SARAM"
// operation. The 2802x Boot Mode table is shown below.
// For information on configuring the boot mode of an eZdsp,
// please refer to the documentation included with the eZdsp,
//
// $Boot_Table
// While an emulator is connected to your device, the TRSTn pin = 1,
// which sets the device into EMU_BOOT boot mode. In this mode, the
// peripheral boot modes are as follows:
//
// Boot Mode: EMU_KEY EMU_BMODE
// (0xD00) (0xD01)
// ---------------------------------------
// Wait !=0x55AA X
// I/O 0x55AA 0x0000
// SCI 0x55AA 0x0001
// Wait 0x55AA 0x0002
// Get_Mode 0x55AA 0x0003
// SPI 0x55AA 0x0004
// I2C 0x55AA 0x0005
// OTP 0x55AA 0x0006
// Wait 0x55AA 0x0007
// Wait 0x55AA 0x0008
// SARAM 0x55AA 0x000A <-- "Boot to SARAM"
// Flash 0x55AA 0x000B
// Wait 0x55AA Other
//
// Write EMU_KEY to 0xD00 and EMU_BMODE to 0xD01 via the debugger
// according to the Boot Mode Table above. Build/Load project,
// Reset the device, and Run example
//
// $End_Boot_Table
//
// DESCRIPTION:
//
// This program will write 1-14 words to EEPROM and read them back.
// The data written and the EEPROM address written to are contained
// in the message structure, I2cMsgOut1. The data read back will be
// contained in the message structure I2cMsgIn1.
//
// This program will work with the on-board I2C EEPROM supplied on
// the F2802x eZdsp.
//
//
//###########################################################################
// Original Author: D.F.
//
// $TI Release: 2802x C/C++ Header Files V1.26 $
// $Release Date: February 2, 2010 $
//###########################################################################
#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
// Note: I2C Macros used in this example can be found in the
// DSP2802x_I2C_defines.h file
// Prototype statements for functions found within this file.
void I2CA_Init(void);
Uint16 I2CA_WriteData(struct I2CMSG *msg);
Uint16 I2CA_ReadData(struct I2CMSG *msg);
interrupt void i2c_int1a_isr(void);
void pass(void);
void fail(void);
// Global variables
// Two bytes will be used for the outgoing address,
// thus only setup 14 bytes maximum
struct I2CMSG I2cMsgOut1={I2C_MSGSTAT_SEND_WITHSTOP,
I2C_SLAVE_ADDR,
I2C_NUMBYTES,
I2C_EEPROM_HIGH_ADDR,
I2C_EEPROM_LOW_ADDR,
0x12, // Msg Byte 1
0x34}; // Msg Byte 2
struct I2CMSG *CurrentMsgPtr; // Used in interrupts
Uint16 PassCount;
Uint16 FailCount;
void main(void)
{
Uint16 Error;
Uint16 i;
CurrentMsgPtr = &I2cMsgOut1;
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2802x_SysCtrl.c file.
InitSysCtrl();
// Step 2. Initalize GPIO:
// This example function is found in the DSP2802x_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 DSP2802x_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 DSP2802x_DefaultIsr.c.
// This function is found in DSP2802x_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 DSP2802x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
I2CA_Init();
// Step 5. User specific code
// Clear Counters
PassCount = 0;
FailCount = 0;
// Clear incoming message buffer
for (i = 0; i < (I2C_MAX_BUFFER_SIZE - 2); i++)
{
I2cMsgIn1.MsgBuffer = 0x0000;
}
// 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;
// Application loop
for(;;)
{
//////////////////////////////////
// Write data to EEPROM section //
//////////////////////////////////
// Check the outgoing message to see if it should be sent.
// In this example it is initialized to send with a stop bit.
if(I2cMsgOut1.MsgStatus == I2C_MSGSTAT_SEND_WITHSTOP)
{
Error = I2CA_WriteData(&I2cMsgOut1);
// If communication is correctly initiated, set msg status to busy
// and update CurrentMsgPtr for the interrupt service routine.
// Otherwise, do nothing and try again next loop. Once message is
// initiated, the I2C interrupts will handle the rest. Search for
// ICINTR1A_ISR in the i2c_eeprom_isr.c file.
if (Error == I2C_SUCCESS)
{
CurrentMsgPtr = &I2cMsgOut1;
I2cMsgOut1.MsgStatus = I2C_MSGSTAT_WRITE_BUSY;
}
} // end of write section
///////////////////////////////////
// Read data from EEPROM section //
///////////////////////////////////
// Check outgoing message status. Bypass read section if status is
// not inactive.
if (I2cMsgOut1.MsgStatus == I2C_MSGSTAT_INACTIVE)
{
// Check incoming message status.
if(I2cMsgIn1.MsgStatus == I2C_MSGSTAT_SEND_NOSTOP)
{
// EEPROM address setup portion
while(I2CA_ReadData(&I2cMsgIn1) != I2C_SUCCESS)
{
// Maybe setup an attempt counter to break an infinite while
// loop. The EEPROM will send back a NACK while it is performing
// a write operation. Even though the write communique is
// complete at this point, the EEPROM could still be busy
// programming the data. Therefore, multiple attempts are
// necessary.
}
// Update current message pointer and message status
CurrentMsgPtr = &I2cMsgIn1;
I2cMsgIn1.MsgStatus = I2C_MSGSTAT_SEND_NOSTOP_BUSY;
}
// Once message has progressed past setting up the internal address
// of the EEPROM, send a restart to read the data bytes from the
// EEPROM. Complete the communique with a stop bit. MsgStatus is
// updated in the interrupt service routine.
else if(I2cMsgIn1.MsgStatus == I2C_MSGSTAT_RESTART)
{
// Read data portion
while(I2CA_ReadData(&I2cMsgIn1) != I2C_SUCCESS)
{
// Maybe setup an attempt counter to break an infinite while
// loop.
}
// Update current message pointer and message status
CurrentMsgPtr = &I2cMsgIn1;
I2cMsgIn1.MsgStatus = I2C_MSGSTAT_READ_BUSY;
}
} // end of read section
// I2CCLK = SYSCLK/(I2CPSC+1)
#if (CPU_FRQ_40MHZ||CPU_FRQ_50MHZ)
I2caRegs.I2CPSC.all = 4; // Prescaler - need 7-12 Mhz on module clk
#endif
#if (CPU_FRQ_60MHZ)
I2caRegs.I2CPSC.all = 6; // Prescaler - need 7-12 Mhz on module clk
#endif
I2caRegs.I2CCLKL = 10; // NOTE: must be non zero
I2caRegs.I2CCLKH = 5; // 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
// Wait until the STP bit is cleared from any previous master communication.
// Clearing of this bit by the module is delayed until after the SCD bit is
// set. If this bit is not checked prior to initiating a new message, the
// I2C could get confused.
if (I2caRegs.I2CMDR.bit.STP == 1)
{
return I2C_STP_NOT_READY_ERROR;
}
// Check if bus busy
if (I2caRegs.I2CSTR.bit.BB == 1)
{
return I2C_BUS_BUSY_ERROR;
}
// Setup number of bytes to send
// MsgBuffer + Address
I2caRegs.I2CCNT = msg->NumOfBytes+2;
// Setup data to send
I2caRegs.I2CDXR = msg->MemoryHighAddr;
I2caRegs.I2CDXR = msg->MemoryLowAddr;
// for (i=0; iNumOfBytes-2; i++)
for (i=0; iNumOfBytes; i++)
{
I2caRegs.I2CDXR = *(msg->MsgBuffer+i);
}
// Send start as master transmitter
I2caRegs.I2CMDR.all = 0x6E20;
return I2C_SUCCESS;
}
Uint16 I2CA_ReadData(struct I2CMSG *msg)
{
// Wait until the STP bit is cleared from any previous master communication.
// Clearing of this bit by the module is delayed until after the SCD bit is
// set. If this bit is not checked prior to initiating a new message, the
// I2C could get confused.
if (I2caRegs.I2CMDR.bit.STP == 1)
{
return I2C_STP_NOT_READY_ERROR;
}
I2caRegs.I2CSAR = msg->SlaveAddress;
if(msg->MsgStatus == I2C_MSGSTAT_SEND_NOSTOP)
{
// Check if bus busy
if (I2caRegs.I2CSTR.bit.BB == 1)
{
return I2C_BUS_BUSY_ERROR;
}
I2caRegs.I2CCNT = 2;
I2caRegs.I2CDXR = msg->MemoryHighAddr;
I2caRegs.I2CDXR = msg->MemoryLowAddr;
I2caRegs.I2CMDR.all = 0x2620; // Send data to setup EEPROM address
}
else if(msg->MsgStatus == I2C_MSGSTAT_RESTART)
{
I2caRegs.I2CCNT = msg->NumOfBytes; // Setup how many bytes to expect
I2caRegs.I2CMDR.all = 0x2C20; // Send restart as master receiver
}
// Interrupt source = stop condition detected
if(IntSource == I2C_SCD_ISRC)
{
// If completed message was writing data, reset msg to inactive state
if (CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_WRITE_BUSY)
{
CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_INACTIVE;
}
else
{
// If a message receives a NACK during the address setup portion of the
// EEPROM read, the code further below included in the register access ready
// interrupt source code will generate a stop condition. After the stop
// condition is received (here), set the message status to try again.
// User may want to limit the number of retries before generating an error.
if(CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_SEND_NOSTOP_BUSY)
{
CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_SEND_NOSTOP;
}
// If completed message was reading EEPROM data, reset msg to inactive state
// and read data from FIFO.
else if (CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_READ_BUSY)
{
CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_INACTIVE;
for(i=0; i < I2C_NUMBYTES; i++)
{
CurrentMsgPtr->MsgBuffer = I2caRegs.I2CDRR;
}
{
// Check recieved data
for(i=0; i < I2C_NUMBYTES; i++)
{
if(I2cMsgIn1.MsgBuffer == I2cMsgOut1.MsgBuffer)
{
PassCount++;
}
else
{
FailCount++;
}
}
if(PassCount == I2C_NUMBYTES)
{
pass();
}
else
{
fail();
}
}
}
}
} // end of stop condition detected
// Interrupt source = Register Access Ready
// This interrupt is used to determine when the EEPROM address setup portion of the
// read data communication is complete. Since no stop bit is commanded, this flag
// tells us when the message has been sent instead of the SCD flag. If a NACK is
// received, clear the NACK bit and command a stop. Otherwise, move on to the read
// data portion of the communication.
else if(IntSource == I2C_ARDY_ISRC)
{
if(I2caRegs.I2CSTR.bit.NACK == 1)
{
I2caRegs.I2CMDR.bit.STP = 1;
I2caRegs.I2CSTR.all = I2C_CLR_NACK_BIT;
}
else if(CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_SEND_NOSTOP_BUSY)
{
CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_RESTART;
}
} // end of register access ready
else
{
// Generate some error due to invalid interrupt source
asm(" ESTOP0");
}
//===========================================================================
// No more.
//===========================================================================
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