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EK-TM4C123GXL: Program doesn't start on power on, only when flashed/debugging or resetting with a button

Part Number: EK-TM4C123GXL

Hi,

So I haven't noticed this before but everytime I start the tiva board, the code does not seem to work. When I debug it or reflash it, everything works as expected. I also don't have the issue if I power on and then press a reset button. What could be the issue? Let me know what information I could provide for resolving the problem.

I am using UART ISRs for sensors and one of them is to communicated with a BeagleBone. Below is my startup_ccs file:

//*****************************************************************************
//
// startup_ccs.c - Startup code for use with TI's Code Composer Studio.
//
// Copyright (c) 2012-2017 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
//
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
//
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 2.1.4.178 of the EK-TM4C123GXL Firmware Package.
//
//*****************************************************************************

#include <stdint.h>
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"

//*****************************************************************************
//
// Forward declaration of the default fault handlers.
//
//*****************************************************************************
void ResetISR(void);
static void NmiSR(void);
static void FaultISR(void);
static void IntDefaultHandler(void);

//*****************************************************************************
//
// External declaration for the reset handler that is to be called when the
// processor is started
//
//*****************************************************************************
extern void _c_int00(void);

//*****************************************************************************
//
// Linker variable that marks the top of the stack.
//
//*****************************************************************************
extern uint32_t __STACK_TOP;

//*****************************************************************************
//
// External declaration for the interrupt handler used by the application.
//
//*****************************************************************************
extern void UART1IntHandler(void);
extern void UART3IntHandler(void);
extern void UART4IntHandler(void);
extern void UART5IntHandler(void);

//*****************************************************************************
//
// The vector table.  Note that the proper constructs must be placed on this to
// ensure that it ends up at physical address 0x0000.0000 or at the start of
// the program if located at a start address other than 0.
//
//*****************************************************************************
#pragma DATA_SECTION(g_pfnVectors, ".intvecs")
void (* const g_pfnVectors[])(void) =
{
    (void (*)(void))((uint32_t)&__STACK_TOP),
                                            // The initial stack pointer
    ResetISR,                               // The reset handler
    NmiSR,                                  // The NMI handler
    FaultISR,                               // The hard fault handler
    IntDefaultHandler,                      // The MPU fault handler
    IntDefaultHandler,                      // The bus fault handler
    IntDefaultHandler,                      // The usage fault handler
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // SVCall handler
    IntDefaultHandler,                      // Debug monitor handler
    0,                                      // Reserved
    IntDefaultHandler,                      // The PendSV handler
    IntDefaultHandler,                      // The SysTick handler
    IntDefaultHandler,                      // GPIO Port A
    IntDefaultHandler,                      // GPIO Port B
    IntDefaultHandler,                      // GPIO Port C
    IntDefaultHandler,                      // GPIO Port D
    IntDefaultHandler,                      // GPIO Port E
    IntDefaultHandler,                         // UART0 Rx and Tx
    UART1IntHandler,                      // UART1 Rx and Tx
    IntDefaultHandler,                      // SSI0 Rx and Tx
    IntDefaultHandler,                      // I2C0 Master and Slave
    IntDefaultHandler,                      // PWM Fault
    IntDefaultHandler,                      // PWM Generator 0
    IntDefaultHandler,                      // PWM Generator 1
    IntDefaultHandler,                      // PWM Generator 2
    IntDefaultHandler,                      // Quadrature Encoder 0
    IntDefaultHandler,                      // ADC Sequence 0
    IntDefaultHandler,                      // ADC Sequence 1
    IntDefaultHandler,                      // ADC Sequence 2
    IntDefaultHandler,                      // ADC Sequence 3
    IntDefaultHandler,                      // Watchdog timer
    IntDefaultHandler,                      // Timer 0 subtimer A
    IntDefaultHandler,                      // Timer 0 subtimer B
    IntDefaultHandler,                      // Timer 1 subtimer A
    IntDefaultHandler,                      // Timer 1 subtimer B
    IntDefaultHandler,                      // Timer 2 subtimer A
    IntDefaultHandler,                      // Timer 2 subtimer B
    IntDefaultHandler,                      // Analog Comparator 0
    IntDefaultHandler,                      // Analog Comparator 1
    IntDefaultHandler,                      // Analog Comparator 2
    IntDefaultHandler,                      // System Control (PLL, OSC, BO)
    IntDefaultHandler,                      // FLASH Control
    IntDefaultHandler,                      // GPIO Port F
    IntDefaultHandler,                      // GPIO Port G
    IntDefaultHandler,                      // GPIO Port H
    IntDefaultHandler,                      // UART2 Rx and Tx
    IntDefaultHandler,                      // SSI1 Rx and Tx
    IntDefaultHandler,                      // Timer 3 subtimer A
    IntDefaultHandler,                      // Timer 3 subtimer B
    IntDefaultHandler,                      // I2C1 Master and Slave
    IntDefaultHandler,                      // Quadrature Encoder 1
    IntDefaultHandler,                      // CAN0
    IntDefaultHandler,                      // CAN1
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // Hibernate
    IntDefaultHandler,                      // USB0
    IntDefaultHandler,                      // PWM Generator 3
    IntDefaultHandler,                      // uDMA Software Transfer
    IntDefaultHandler,                      // uDMA Error
    IntDefaultHandler,                      // ADC1 Sequence 0
    IntDefaultHandler,                      // ADC1 Sequence 1
    IntDefaultHandler,                      // ADC1 Sequence 2
    IntDefaultHandler,                      // ADC1 Sequence 3
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // GPIO Port J
    IntDefaultHandler,                      // GPIO Port K
    IntDefaultHandler,                      // GPIO Port L
    IntDefaultHandler,                      // SSI2 Rx and Tx
    IntDefaultHandler,                      // SSI3 Rx and Tx
    UART3IntHandler,                      // UART3 Rx and Tx
    UART4IntHandler,                      // UART4 Rx and Tx
    UART5IntHandler,                      // UART5 Rx and Tx
    IntDefaultHandler,                      // UART6 Rx and Tx
    IntDefaultHandler,                      // UART7 Rx and Tx
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // I2C2 Master and Slave
    IntDefaultHandler,                      // I2C3 Master and Slave
    IntDefaultHandler,                      // Timer 4 subtimer A
    IntDefaultHandler,                      // Timer 4 subtimer B
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // Timer 5 subtimer A
    IntDefaultHandler,                      // Timer 5 subtimer B
    IntDefaultHandler,                      // Wide Timer 0 subtimer A
    IntDefaultHandler,                      // Wide Timer 0 subtimer B
    IntDefaultHandler,                      // Wide Timer 1 subtimer A
    IntDefaultHandler,                      // Wide Timer 1 subtimer B
    IntDefaultHandler,                      // Wide Timer 2 subtimer A
    IntDefaultHandler,                      // Wide Timer 2 subtimer B
    IntDefaultHandler,                      // Wide Timer 3 subtimer A
    IntDefaultHandler,                      // Wide Timer 3 subtimer B
    IntDefaultHandler,                      // Wide Timer 4 subtimer A
    IntDefaultHandler,                      // Wide Timer 4 subtimer B
    IntDefaultHandler,                      // Wide Timer 5 subtimer A
    IntDefaultHandler,                      // Wide Timer 5 subtimer B
    IntDefaultHandler,                      // FPU
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // I2C4 Master and Slave
    IntDefaultHandler,                      // I2C5 Master and Slave
    IntDefaultHandler,                      // GPIO Port M
    IntDefaultHandler,                      // GPIO Port N
    IntDefaultHandler,                      // Quadrature Encoder 2
    0,                                      // Reserved
    0,                                      // Reserved
    IntDefaultHandler,                      // GPIO Port P (Summary or P0)
    IntDefaultHandler,                      // GPIO Port P1
    IntDefaultHandler,                      // GPIO Port P2
    IntDefaultHandler,                      // GPIO Port P3
    IntDefaultHandler,                      // GPIO Port P4
    IntDefaultHandler,                      // GPIO Port P5
    IntDefaultHandler,                      // GPIO Port P6
    IntDefaultHandler,                      // GPIO Port P7
    IntDefaultHandler,                      // GPIO Port Q (Summary or Q0)
    IntDefaultHandler,                      // GPIO Port Q1
    IntDefaultHandler,                      // GPIO Port Q2
    IntDefaultHandler,                      // GPIO Port Q3
    IntDefaultHandler,                      // GPIO Port Q4
    IntDefaultHandler,                      // GPIO Port Q5
    IntDefaultHandler,                      // GPIO Port Q6
    IntDefaultHandler,                      // GPIO Port Q7
    IntDefaultHandler,                      // GPIO Port R
    IntDefaultHandler,                      // GPIO Port S
    IntDefaultHandler,                      // PWM 1 Generator 0
    IntDefaultHandler,                      // PWM 1 Generator 1
    IntDefaultHandler,                      // PWM 1 Generator 2
    IntDefaultHandler,                      // PWM 1 Generator 3
    IntDefaultHandler                       // PWM 1 Fault
};

//*****************************************************************************
//
// This is the code that gets called when the processor first starts execution
// following a reset event.  Only the absolutely necessary set is performed,
// after which the application supplied entry() routine is called.  Any fancy
// actions (such as making decisions based on the reset cause register, and
// resetting the bits in that register) are left solely in the hands of the
// application.
//
//*****************************************************************************
void
ResetISR(void)
{
    //
    // Jump to the CCS C initialization routine.  This will enable the
    // floating-point unit as well, so that does not need to be done here.
    //
    __asm("    .global _c_int00\n"
          "    b.w     _c_int00");
}

//*****************************************************************************
//
// This is the code that gets called when the processor receives a NMI.  This
// simply enters an infinite loop, preserving the system state for examination
// by a debugger.
//
//*****************************************************************************
static void
NmiSR(void)
{
    //
    // Enter an infinite loop.
    //
    while(1)
    {
    }
}

//*****************************************************************************
//
// This is the code that gets called when the processor receives a fault
// interrupt.  This simply enters an infinite loop, preserving the system state
// for examination by a debugger.
//
//*****************************************************************************
static void
FaultISR(void)
{
    //
    // Enter an infinite loop.
    //
    while(1)
    {
    }
}

//*****************************************************************************
//
// This is the code that gets called when the processor receives an unexpected
// interrupt.  This simply enters an infinite loop, preserving the system state
// for examination by a debugger.
//
//*****************************************************************************
static void
IntDefaultHandler(void)
{
    //
    // Go into an infinite loop.
    //
    while(1)
    {
    }
}


  • New Year Greetings,

    Staff/I (outsiders) 'feel your pain.'

    Following approach is suggested:

    • Kindly substitute one of the vendor's basic/simple projects - noting if this (failed Reset) condition continues - this discovery proves key!
    • Normally the 'Start-Up' file manages the MCU's Reset.    While it 'looks good' - might you replace it (start-up file) with a fresh one - then add your 'file specifics.'
    • You note a 2nd (more powerful) MCU board:
      • have you (recently) checked to insure that a proper 'common ground' exists between both boards?
      • have you measured the voltage at each board - when 'in operation' - to confirm that (both) are being adequately powered?   (Stealing power from the LPad may prove insufficient)
      • kindly test & then describe the results when you, 'Break all connections between the 2 boards.'    (we seek to run the LPad alone!)
    • We've attached a schematic - have you made any connections to 'J2-5' - which (either) imports or exports your LPad's Reset Activity?
    • The LPad 'saves' the use of a capacitor (to ground) at the MCU's Reset Input - 'much minimizing' the effect of the board's 'Power-On' Reset.   Should all else listed here fail - and you have the skill & experience - you may add a 0.1µF ceramic cap to C13's board footprint - or add it such that it contacts J2-P5.
    • As always - you can reduce the likelihood of dreaded 'single-board anomalies' (which 'eat' helper's time/effort) by acquiring & then testing a 2nd board.  (LPad here)

    Again that top bullet point proves easiest - and will provide key diagnostic feedback.     Note that we have >100 of these '123 LPads - all working - & all minus C13...

  • Thank you for your response.

    As expected. the first bullet point worked out. I uploaded "uart_echo" project example as I suspected something would be wrong with interrupts I decided to choose this one due to that reason. I worked as expected even after power on cycle. Note that I have done this on the same board as I had issues in the original question.

    Trying to find out where the problem may lay, I also copied a working startup file and added the interrupt handlers from the old one and the problem persisted. So what I noticed was that I had enabled a uart port that wasn't used for anything, i guess it was a leftover when I used to plug it using micro USB cable. When I disabled the UART0 (it had no interrupt sequence, it wasn't connected to anything), it started working from power ON. This is strange for me why that fixed the issue but here it is. Thank you for the thourough reply, will keep a note for it for future if I encounter the problem again.

  • Successful diagnostic greetings,

    Thank you for your nicely detailed reply.     Neither staff nor I could agree that an, 'Unused UART Port's enabling' could cause your, 'Start-Up Issue' ... except for the fact that UART_0 (on the '123 LPad) serves as your ICDI channel!     (and its 're-order' for other use often proves unwise.)

    Good that you're now working - might you click 'This Resolved' button which appears at the base of my team's successful diagnosis posting?