The provided code is a C function named `MainInit` that...

September 4, 2025 at 09:42 AM


UINT16 MainInit(void)
{
    UINT16 Error = 0;
/*Hardware init function need to be called from the application layer*/

#ifdef SET_EEPROM_PTR
    SET_EEPROM_PTR
#endif


/* Reset application function pointer*/




    /* ECATCHANGE_START(V5.13) COE4*/
    pAPPL_CoeReadInd = NULL;
    pAPPL_CoeWriteInd = NULL;
    /* ECATCHANGE_END(V5.13) COE4*/

    pAPPL_MainLoop = NULL;

    /* initialize the EtherCAT Slave Interface */
    ECAT_Init();
    /* initialize the objects */
    COE_ObjInit();


    /*indicate that the slave stack initialization finished*/
    bInitFinished = TRUE;


    bMinCycleTimeMeasurementStarted = FALSE;
    u32CycleTimeStartValue = 0;
    u32MinCycleTimeStartValue = 0;

    u32SystemTimeReadFailure = 0;

    /* Get the System Time read failure */
    {
       UINT32 u32TimeValue = 0;
       UINT32 u32Cnt = 0;
       UINT32 u32Delta = 0;

       while (u32Cnt < 1000)
       {
           HW_EscReadDWordIsr(u32TimeValue, ESC_SYSTEMTIME_OFFSET);
           HW_EscReadDWordIsr(u32Delta, ESC_SYSTEMTIME_OFFSET);

            if (u32TimeValue <= u32Delta)
            {
                    u32Delta = u32Delta - u32TimeValue;
            }
            else
            {
                //The 32Bit timer is wrapped around
                u32Delta = u32Delta + (0xFFFFFFFF - u32TimeValue);
            }


            if (u32SystemTimeReadFailure == 0)
            {
                u32SystemTimeReadFailure = u32Delta;
            }
            else if (u32SystemTimeReadFailure > u32Delta)
            {
                u32SystemTimeReadFailure = u32Delta;
            }

          u32Cnt++;
       }
    
    }


/*Application Init need to be called from the application layer*/
     return Error;
}

The provided code is a C function named MainInit that initializes various components in an EtherCAT-based system. Here's a detailed breakdown of what the code does:

Purpose:

The function MainInit initializes the system components for an EtherCAT slave stack. It performs tasks such as hardware initialization, initializing object dictionaries or function pointers, setting up time measurements, and preparing the system for correct operation.

Function Details:

Return Value:
- The function returns a UINT16 value (Error), initialized to 0. This value might potentially contain error codes if initialization steps were to fail, although no error handling is implemented in the current code.
Conditional EEPROM Pointer Setup:
- If the SET_EEPROM_PTR macro is defined, the corresponding hardware initialization logic tied to EEPROM gets executed.
Function Pointer Reset:
- Application-level function pointers (pAPPL_CoeReadInd, pAPPL_CoeWriteInd, and pAPPL_MainLoop) are reset to NULL, indicating they are uninitialized.
EtherCAT Slave Initialization:
- Calls ECAT_Init() to initialize the EtherCAT slave stack.
- Calls COE_ObjInit() to initialize the CANopen over EtherCAT (CoE) object dictionary.
Initialization Flags:
- Sets bInitFinished to TRUE, indicating that the initialization phase is complete.
- Prepares variables for measuring the minimum cycle time (bMinCycleTimeMeasurementStarted, u32CycleTimeStartValue, and u32MinCycleTimeStartValue).
- Initializes u32SystemTimeReadFailure to 0 for tracking time read failures.
System Time Read Failure Determination:
- Reads and compares system time values from the EtherCAT slave controller (using HW_EscReadDWordIsr).
- Measures the smallest delta value (u32Delta) between consecutive time reads to detect a minimum cycle time resolution or system time reading failure.
- Stores the smallest delta in u32SystemTimeReadFailure over 1000 iterations for accurate tracking.
Placeholder for Application Layer Initialization:
- The comment indicates that further application-level initializations need to be executed, but the actual application initialization code is not implemented in this function.
Return Statement:
- Returns Error, which is always 0 in the current implementation unless future error handling logic modifies it.

Summary:

In essence, this function sets up the EtherCAT slave stack, initializes function pointers and hardware interfaces, and measures the system time read failure behavior. It is part of the lower-level initialization process required for an EtherCAT communication stack in an embedded system. However, application-specific initialization and error handling need to be implemented in related functions outside this routine.

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