TMS320F280049: LIN example code: receive data with polling method

//#############################################################################
//
// FILE:   lin_ex1_loopback_interrupts.c
//
// TITLE:   LIN Internal Loopback with Interrupts
//
//! \addtogroup driver_example_list
//! <h1> LIN Internal Loopback with Interrupts </h1>
//!
//!  This example configures the LIN module in master mode for internal
//!  loopback with interrupts. The module is setup to perform 8 data
//!  transmissions with different transmit IDs and varying transmit data.
//!  Upon reception of an ID header, an interrupt is triggered on line 0
//!  and an interrupt service routine (ISR) is called. The received data
//!  is then checked for accuracy.
//!
//! \note The example can be adjusted to use interrupt line 1 instead of line 0
//! by un-commenting "LIN_setInterruptLevel1()"
//!
//! \b External \b Connections \n
//!  - None.
//!
//! \b Watch \b Variables \n
//!  - txData - An array with the data being sent
//!  - rxData - An array with the data that was received
//!  - result - The example completion status (PASS = 0xABCD, FAIL = 0xFFFF)
//!  - level0Count - The number of line 0 interrupts
//!  - level1Count - The number of line 1 interrupts
//!
//
//#############################################################################
// $TI Release: F28004x Support Library v1.07.00.00 $
// $Release Date: Sun Sep 29 07:29:19 CDT 2019 $
// $Copyright:
// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
//
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// modification, are permitted provided that the following conditions 
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// 
//   Redistributions of source code must retain the above copyright 
//   notice, this list of conditions and the following disclaimer.
// 
//   Redistributions in binary form must reproduce the above copyright
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//   distribution.
// 
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// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//#############################################################################

//
// Included Files
//
#include "driverlib.h"
#include "device.h"

//
// Defines
//
#define FRAME_LENGTH    0x8
#define LIN_PASS        0xABCD
#define LIN_FAIL        0xFFFF

//
// Globals
//
volatile uint32_t level0Count = 0;
volatile uint32_t level1Count = 0;
volatile uint32_t vectorOffset = 0;
uint16_t result;
uint16_t txData[8] = {0x11, 0x34, 0x56, 0x78, 0x9A, 0xAB, 0xCD, 0xEF};
uint16_t rxData[8] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

//
// Function Prototypes
//
__interrupt void level0ISR(void);
__interrupt void level1ISR(void);

//
// Main
//
void main(void)
{
    uint32_t i, dataIndex;
    uint16_t txID, error;

    //
    // Initialize device clock and peripherals
    //
    Device_init();

    //
    // Initialize GPIO and configure GPIO pins for LINTX/LINRX
    //
    Device_initGPIO();
    GPIO_setPinConfig(DEVICE_GPIO_CFG_LINTXA);
    GPIO_setPinConfig(DEVICE_GPIO_CFG_LINRXA);

    //
    // Initialize PIE and clear PIE registers. Disables CPU interrupts.
    //
    Interrupt_initModule();

    //
    // Initialize the PIE vector table with pointers to the shell Interrupt
    // Service Routines (ISR).
    //
    Interrupt_initVectorTable();
    EINT;
    ERTM;

    //
    // Interrupts that are used in this example are re-mapped to
    // ISR functions found within this file.
    // This registers the interrupt handler in PIE vector table.
    //
    //Interrupt_register(INT_LINA_0, &level0ISR);
    //Interrupt_register(INT_LINA_1, &level1ISR);

    //
    // Enable the LIN interrupt signals
    //
    //Interrupt_enable(INT_LINA_0);
    //Interrupt_enable(INT_LINA_1);

    //
    // Initialize the LIN module
    //
    LIN_initModule(LINA_BASE); // To slave mode

    //
    // Enable Internal Loopback mode
    //
    LIN_enableIntLoopback(LINA_BASE);

    //
    // Enable interrupts for when an header identifier is received
    //
    //LIN_enableInterrupt(LINA_BASE, LIN_INT_ID);

    //
    // Set the interrupt priority line
    // Default is set to Interrupt line 0 (high priority)
    // Comment out "LIN_setInterruptLevel0" and uncomment
    // "LIN_setInterruptLevel1" to change to interrupt line 1 (low priority)
    //
    //LIN_setInterruptLevel0(LINA_BASE, LIN_INT_ALL);
    //LIN_setInterruptLevel1(LINA_BASE, LIN_INT_ALL);

    //
    // Enable parity check
    //
    LIN_enableParity(LINA_BASE);

    //
    // Enable global interrupt lines and clear status to known value
    //
//    LIN_enableGlobalInterrupt(LINA_BASE, LIN_INTERRUPT_LINE0);
//    LIN_enableGlobalInterrupt(LINA_BASE, LIN_INTERRUPT_LINE1);
//    LIN_clearGlobalInterruptStatus(LINA_BASE, LIN_INTERRUPT_LINE0);
//    LIN_clearGlobalInterruptStatus(LINA_BASE, LIN_INTERRUPT_LINE1);

    //
    // Perform 8 data transmissions with different transmit IDs and varying
    // number of bytes transmitted. Received data is checked for correctness.
    //
    for(i = 1 ; i <= FRAME_LENGTH; i++)
    {
        vectorOffset = 0;

        //
        // Create a new transmit ID and update with parity bits
        //
        txID = (0x10 + i);
        txID = LIN_generateParityID(txID);

        //
        // Increment the value of the first 8-bits of the transmitted
        // message data
        //
        txData[0]++;

        //
        // Reset values in receive buffer array
        //
        for(dataIndex=0; dataIndex < 8; dataIndex++)
        {
            rxData[dataIndex] = 0xFF;
        }

        //
        // Set the frame length (number of bytes to be transmitted)
        //
        LIN_setFrameLength(LINA_BASE, i);

        //
        // This places data into the transmit buffer.
        // No ID or data is placed on the bus and transmitted yet.
        //
        LIN_sendData(LINA_BASE, txData);

        //
        // Set the message ID to initiate a header transmission.
        // This causes the ID to be written to the bus followed by the
        // data in the transmit buffers.
        //
        LIN_setIDByte(LINA_BASE, txID);

        //
        // Wait for ISR to trigger and run upon reception of the ID header
        //
        //while(vectorOffset != LIN_VECT_ID);

        //
        // Wait until Transmit buffer is empty and has completed transmission
        //
        while(!LIN_isTxBufferEmpty(LINA_BASE));

        //while(length = (uint32_t)(HWREG(LINA_BASE + LIN_SCIFLR_RXRDY) |);

        //
        // Read the received data in the receive buffers
        //
        LIN_getData(LINA_BASE, rxData);

        //
        // Verify the transmitted data matches the received data
        //
        for (dataIndex=0; dataIndex < i; dataIndex++)
        {
            if (rxData[dataIndex] != txData[dataIndex])
            {
                error++;
            }
        }
    }

    //
    // Check if any data errors occurred
    //
    if(error == 0)
    {
        result = LIN_PASS;
    }
    else
    {
      result = LIN_FAIL;
    }

    //
    // Example completed. Check "result" variable for completion status.
    //
    asm("   ESTOP0");
}

//
// LIN High Priority (Level 0) ISR - Interrupt service routine for interrupt
// line 0. This ISR saves the offset vector indicating the current highest
// priority pending interrupt.
//
__interrupt void
level0ISR(void)
{
    //
    // Increment the interrupt count
    //
    level0Count++;

    //
    // Read the high priority interrupt vector
    //
    vectorOffset = LIN_getInterruptLine0Offset(LINA_BASE);
    LIN_clearInterruptStatus(LINA_BASE, LIN_INT_ID);
    LIN_clearGlobalInterruptStatus(LINA_BASE, LIN_INTERRUPT_LINE0);

    //
    // Acknowledge this interrupt located in group 8
    //
    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP8);
}

//
// LIN Low Priority (Level 1) ISR - Interrupt service routine for interrupt
// line 1. This ISR saves the offset vector indicating the current highest
// priority pending interrupt.
//
__interrupt void
level1ISR(void)
{
    //
    // Increment the interrupt count
    //
    level1Count++;

    //
    // Read the low priority interrupt vector
    //
    vectorOffset = LIN_getInterruptLine1Offset(LINA_BASE);
    LIN_clearInterruptStatus(LINA_BASE, LIN_INT_ID);
    LIN_clearGlobalInterruptStatus(LINA_BASE, LIN_INTERRUPT_LINE1);

    //
    // Acknowledge this interrupt located in group 8
    //
    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP8);
}

//
// End of File
//

    while(1){
            while(LIN_isRxMatch(LINA_BASE)){
                //
                // Read the received data in the receive buffers
                //
                LIN_getData(LINA_BASE, rxData);
                }
            }