// TI File $Revision: /main/3 $
// Checkin $Date: December 3, 2004   13:40:48 $
//###########################################################################
//
// FILE:    Example_280xI2c_eeprom.c
//
// TITLE:   DSP280x I2C EEPROM Example
//
// ASSUMPTIONS:
//
//    This program requires the DSP280x 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 280x 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      GPIO18     GPIO29    GPIO34
//       Mode      SPICLKA    SCITXDA
//                  SCITXB
//       -------------------------------------
//       Flash       1          1        1
//       SCI-A       1          1        0
//       SPI-A       1          0        1
//       I2C-A       1          0        0
//       ECAN-A      0          1        1        
//       SARAM       0          1        0  <- "boot to SARAM"
//       OTP         0          0        1
//       I/0         0          0        0 
//
// 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 F280x eZdsp.
//
//
//###########################################################################
// Original Author: D.F.
//
// $TI Release: DSP280x, DSP2801x Header Files V1.41 $
// $Release Date: August 7th, 2006 $
//###########################################################################


#include "DSP280x_Device.h"     // DSP280x Headerfile Include File
#include "DSP280x_Examples.h"   // DSP280x Examples Include File

// Note: I2C Macros used in this example can be found in the 
// DSP280x_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);

#define I2C_SLAVE_ADDR        0x50
#define I2C_NUMBYTES          4
#define I2C_EEPROM_HIGH_ADDR  0x00
#define I2C_EEPROM_LOW_ADDR   0x30

// 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
                          0x56,                   // Msg Byte 3
                          0x78,                   // Msg Byte 4
                          0x9A,                   // Msg Byte 5      
                          0xBC,                   // Msg Byte 6
                          0xDE,                   // Msg Byte 7
                          0xF0,                   // Msg Byte 8
                          0x11,                   // Msg Byte 9
                          0x10,                   // Msg Byte 10
                          0x11,                   // Msg Byte 11 
                          0x12,                   // Msg Byte 12
                          0x13,                   // Msg Byte 13
                          0x12};                  // Msg Byte 14
                                            
                          
struct I2CMSG I2cMsgIn1={ I2C_MSGSTAT_SEND_NOSTOP, 
                          I2C_SLAVE_ADDR, 
                          I2C_NUMBYTES,
                          I2C_EEPROM_HIGH_ADDR,
                          I2C_EEPROM_LOW_ADDR};
                          
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 DSP280x_SysCtrl.c file.
   InitSysCtrl();


// Step 2. Initalize GPIO: 
// This example function is found in the DSP280x_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 DSP280x_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 DSP280x_DefaultIsr.c.
// This function is found in DSP280x_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 DSP280x_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; i++)
   {
       I2cMsgIn1.MsgBuffer[i] = 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;
         }