//###########################################################################
//
// FILE:    Example_2837xDI2C_eeprom.c
//
// TITLE:   I2C EEPROM Example
//
//! \addtogroup cpu01_example_list
//! <h1>I2C EEPROM Example (i2c_eeprom)</h1>
//!
//! 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.
//!
//! \b External \b Connections \n
//! - This program requires an external I2C EEPROM connected to
//!   the I2C bus at address 0x50.
//!
//
//###########################################################################
// $TI Release: F2837xD Support Library v210 $
// $Release Date: Tue Nov  1 14:46:15 CDT 2016 $
// $Copyright: Copyright (C) 2013-2016 Texas Instruments Incorporated -
//             http://www.ti.com/ ALL RIGHTS RESERVED $
//###########################################################################

//
// Included Files
//
#include "F28x_Project.h"

//
// Defines
//
#define I2C_SLAVE_ADDR        0x50
#define I2C_NUMBYTES          2
#define I2C_EEPROM_HIGH_ADDR  0x00
#define I2C_EEPROM_LOW_ADDR   0x30

//
// Globals
//
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 I2cMsgIn1={ I2C_MSGSTAT_SEND_NOSTOP,
                          I2C_SLAVE_ADDR,
                          I2C_NUMBYTES,
                          I2C_EEPROM_HIGH_ADDR,
                          I2C_EEPROM_LOW_ADDR};

struct I2CMSG *CurrentMsgPtr;
Uint16 PassCount;
Uint16 FailCount;

//
// Function Prototypes
//
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);

//
// Main
//
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 F2837xD_SysCtrl.c file.
//
   InitSysCtrl();

//
// Step 2. Initialize GPIO:
// This example function is found in the F2837xD_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
//
   InitGpio();

//
// For this example, only init the pins for the SCI-A port.
// These functions are found in the F2837xD_Gpio.c file.
//
   GPIO_SetupPinMux(32, GPIO_MUX_CPU1, 1);
   GPIO_SetupPinMux(33, GPIO_MUX_CPU1, 1);

//
// 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 F2837xD_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 F2837xD_DefaultIsr.c.
// This function is found in F2837xD_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.I2CA_INT = &i2c_int1a_isr;
   EDIS;      // This is needed to disable write to EALLOW protected registers

//
// Step 4. Initialize the Device Peripherals:
//
   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;

   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;
         }
      }

      //
      // 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;
         }
      }
   }
}

//
// I2CA_Init - Initialize I2CA settings
//
void I2CA_Init(void)
{
   I2caRegs.I2CSAR.all = 0x0050;     // Slave address - EEPROM control code

   I2caRegs.I2CPSC.all = 6;          // Prescaler - need 7-12 Mhz on module clk
   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

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

   return;
}

//
// I2CA_WriteData - Transmit I2CA message
//
Uint16 I2CA_WriteData(struct I2CMSG *msg)
{
   Uint16 i;

   //
   // 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;
   }

   //
   // Setup slave address
   //
   I2caRegs.I2CSAR.all = msg->SlaveAddress;

   //
   // 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.all = msg->MemoryHighAddr;
   I2caRegs.I2CDXR.all = msg->MemoryLowAddr;

   for (i=0; i < msg->NumOfBytes; i++)
   {
      I2caRegs.I2CDXR.all = *(msg->MsgBuffer+i);
   }

   //
   // Send start as master transmitter
   //
   I2caRegs.I2CMDR.all = 0x6E20;

   return I2C_SUCCESS;
}

//
// I2CA_ReadData - Read I2CA Message
//
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.all = 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.all = msg->MemoryHighAddr;
      I2caRegs.I2CDXR.all = 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
   }

   return I2C_SUCCESS;
}

//
// i2c_int1a_isr - I2CA ISR
//
__interrupt void i2c_int1a_isr(void)
{
   Uint16 IntSource, i;

   //
   // Read __interrupt source
   //
   IntSource = I2caRegs.I2CISRC.all;

   //
   // 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[i] = I2caRegs.I2CDRR.all;
            }
        {
         //
         // Check received data
         //
         for(i=0; i < I2C_NUMBYTES; i++)
         {
            if(I2cMsgIn1.MsgBuffer[i] == I2cMsgOut1.MsgBuffer[i])
            {
                PassCount++;
            }
            else
            {
                FailCount++;
            }
         }
         if(PassCount == I2C_NUMBYTES)
         {
            pass();
         }
         else
         {
            fail();
         }
        }
       }
     }
   }

   //
   // 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;
      }
   }
   else
   {
      //
      // Generate some error due to invalid __interrupt source
      //
      asm("   ESTOP0");
   }

   //
   // Enable future I2C (PIE Group 8) __interrupts
   //
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP8;
}

//
// pass - Halt debugger and signify pass
//
void pass()
{
   asm("   ESTOP0");
   for(;;);
}

//
// fail - Halt debugger and signify fail
//
void fail()
{
   asm("   ESTOP0");
   for(;;);
}

//
// End of file
//
