Strange logic problem after compilation in CUBE IDE 1.14.1

[kevinKang]

Hi all,

    basic info:

    stm32 CUBE IDE v1.14.1

    PC: Win10 64bit

    MCU:STM32G0B1CC

    In my code, there are two functions to control the battery to enter charge mode from init mode, when the battery receive a command. Check_AuthCmdToCHG（）will set CANOpenStruct.flag_authCmdGotoCHG to STD_TRUE and set CANOpenStruct.sendTPDOInfo STD_TRUE. 

   normally，after CANOpenStruct.flag_authCmdGotoCHG be set to  STD_TRUE , CheckFlag_InitGotoCHG() will make state machine FSM goes to charge mode.

   But it's very strange, i send a command to MCU, then I receive TPDO info from CAN bus, this means CANOpenStruct.sendTPDOInfo already be set to STD_TRUE. however  CANOpenStruct.flag_authCmdGotoCHG and CheckFlag_InitGotoCHG() are not work!

   When I examined the code, I couldn't find the cause. Therefore, I wrote a test function Test_CANCmd() ready to read CANOpenStruct.flag_authCmdGotoCHG and CANOpenStruct.sendTPDOInfo out, the other did not modify any code!  I compile the code and burn it like before. Then something amazing happened. Everything worked!

   is there anyone can explain this? The Test_CANCmd（）function just uses the value of CANOpenStruct.flag_authCmdGotoCHG, FSMStruct.flag_initGotoCHG and does not change it, why does it have such an effect? 

void Check_AuthCmdToCHG(void)
{
    if(sysInfoStruct.statusCharger == STD_FALSE)
    {
        if(pinStatus_present == STD_ON)
        {
            if(sysInfoStruct.chargerOnline == 0x1234)
            {
                sysInfoStruct.statusCharger = STD_TRUE;
                CANOpenStruct.flag_authCmdGotoCHG = STD_TRUE;
                CANOpenStruct.sendTPDOInfo= STD_TRUE; //if true,it will enable CAN TPDO
            }
        }
        else
        {
            sysInfoStruct.chargerOnline = 0;
        }
    }
}

void CheckFlag_InitGotoCHG(void)
{
    if(pinStatus_present == STD_ON)
    {
        if(CANOpenStruct.flag_authCmdGotoCHG == STD_TRUE)
        {
            CANOpenStruct.flag_authCmdGotoCHG = STD_FALSE;
            FSMStruct.flag_initGotoCHG = STD_TRUE;
        }
    }
}

uint32 Test_CANCmd(union_64bits cmd)
{
    //..........
    switch(cmd.byte[2])
    {
       case 0xF1:
            //......
            break;
       case 0xF5:  //ESD Pres pin onoff times test
                if(cmd.byte[3] == 0xFF)
                {
                    errCode = CANOpenStruct.flag_authCmdGotoCHG;
                }
                else if(cmd.byte[3] == 0xFE)
                {
                    errCode = FSMStruct.flag_initGotoCHG;
                }
                else
                {
                    errCode = TEC_cmdParaErr;
                }
                break;
             //..........
    }
    return errCode;
}

[liaifat85]

If you have debugging enabled, print the values of flag_authCmdGotoCHG, sendTPDOInfo, and FSMStruct.flag_initGotoCHG right after setting and reading them to observe any anomalies.

[kevinKang]

Hi liaifat85,

  Thanks for your feedback!

  My current APP code is address offset because the system comes with a bootloader. I have tried to modify the offset address and directly run online simulation, and the program works normally.

  I have tried the following 2 situations:

  S1:  

  Comment out the code for CANOpenStruct.flag_authCmdGotoCHG and FSMStruct.flag_initGotoCHG , without changing anything else, and the program works abnormally.

uint32 Test_CANCmd(union_64bits cmd)
{
    //..........
    switch(cmd.byte[2])
    {
       case 0xF1:
            //......
            break;
       case 0xF5:  //ESD Pres pin onoff times test
                /*
                if(cmd.byte[3] == 0xFF)
                {
                    errCode = CANOpenStruct.flag_authCmdGotoCHG;
                }
                else if(cmd.byte[3] == 0xFE)
                {
                    errCode = FSMStruct.flag_initGotoCHG;
                }
                else
                {
                    errCode = TEC_cmdParaErr;
                }
                */
                break;
             //..........
    }
    return errCode;
}

 S2:

  Keep CANOpenStruct.flag_authCmdGotoCHG and FSMStruct.flag_initGotoCHG code, do not change other codes, the program works fine.

[kevinKang · Accepted solution]

My problem has been solved!
Root cause: STM32G0B1CC is based on Arm Cortex -M0+ core, it no support unaligned accesses, pay attention to the large structure in your code.