Bit fields keil hardfault after restarting

问题

When I use this struct just after flashing device it works well, but after restarting (power on/off) using this struct(assign to any bit) cause a HardFault irq. I use Keil uVision with STM32F205. Why it not works? and what should I change/remove/add to fix it? Direct using GPIOC->ODR don't cause any problems what is wrong with bitfields in Kail?

#pragma anon_unions

typedef union {
      struct {
        __IO uint16_t Data_Bus:8; // 0-7    data bus
        __IO uint16_t Ctr_Pins:6; // 8-13   control pins
        __IO uint16_t         :2; // 14-15  unused here
    };
    struct {
        __IO uint16_t D0:1; // 0   data bus pin
        __IO uint16_t D1:1; // 1   data bus pin
        __IO uint16_t D2:1; // 2   data bus pin
        __IO uint16_t D3:1; // 3   data bus pin
        __IO uint16_t D4:1; // 4   data bus pin
        __IO uint16_t D5:1; // 5   data bus pin
        __IO uint16_t D6:1; // 6   data bus pin
        __IO uint16_t D7:1; // 7   data bus pin
        // --------------------------------
        __IO uint16_t RS:1; // 8   reset
        __IO uint16_t CS:1; // 9   chip select
        __IO uint16_t CD:1; // 10  control / data
        __IO uint16_t RD:1; // 11  read tick
        __IO uint16_t WR:1; // 12  write tick
        __IO uint16_t EN:1; // 13  enable display
        // ---------------------------------
        __IO uint16_t   :1; // 14  unused
        __IO uint16_t LD:1; // 15  led
    };
} *PC_STRUCT_PTR, PC_STRUCT;

PC_STRUCT_PTR __TMP = (PC_STRUCT_PTR)(GPIOC_BASE+0x14);
#define PINOUTS (*__TMP)

it's used like this:

void Write_Reg(unsigned char command)
{
    PINOUTS.CD = 0; PINOUTS.RD = 1; PINOUTS.CS = 0; PINOUTS.WR = 0;
    PINOUTS.Data_Bus = command; wait();
    PINOUTS.WR = 1; PINOUTS.CS = 1; PINOUTS.CD = 1; wait();
}

回答1:

In file 'startup_stm32f20x.s', make sure that you have the following piece of code:

EXTERN  HardFault_Handler_C        ; this declaration is probably missing

__tx_vectors                       ; this declaration is probably there
    DCD     HardFault_Handler

Then, in the same file, add the following interrupt handler (where all other handlers are located):

    PUBWEAK HardFault_Handler
    SECTION .text:CODE:REORDER(1)
HardFault_Handler
    TST LR, #4
    ITE EQ
    MRSEQ R0, MSP
    MRSNE R0, PSP
    B HardFault_Handler_C

Then, in file 'stm32f2xx.c', add the following ISR:

void HardFault_Handler_C(unsigned int* hardfault_args)
{
    printf("R0    = 0x%.8X\r\n",hardfault_args[0]);         
    printf("R1    = 0x%.8X\r\n",hardfault_args[1]);         
    printf("R2    = 0x%.8X\r\n",hardfault_args[2]);         
    printf("R3    = 0x%.8X\r\n",hardfault_args[3]);         
    printf("R12   = 0x%.8X\r\n",hardfault_args[4]);         
    printf("LR    = 0x%.8X\r\n",hardfault_args[5]);         
    printf("PC    = 0x%.8X\r\n",hardfault_args[6]);         
    printf("PSR   = 0x%.8X\r\n",hardfault_args[7]);         
    printf("BFAR  = 0x%.8X\r\n",*(unsigned int*)0xE000ED38);
    printf("CFSR  = 0x%.8X\r\n",*(unsigned int*)0xE000ED28);
    printf("HFSR  = 0x%.8X\r\n",*(unsigned int*)0xE000ED2C);
    printf("DFSR  = 0x%.8X\r\n",*(unsigned int*)0xE000ED30);
    printf("AFSR  = 0x%.8X\r\n",*(unsigned int*)0xE000ED3C);
    printf("SHCSR = 0x%.8X\r\n",SCB->SHCSR);                
    while (1);
}

If you can't use printf at the point in the execution when this specific Hard-Fault interrupt occurs, then save all the above data in a global buffer instead, so you can view it after reaching the while (1).

Then, refer to the 'Cortex-M Fault Exceptions and Registers' section at http://www.keil.com/appnotes/files/apnt209.pdf in order to understand the problem, or publish the output here if you want further assistance.

来源：https://stackoverflow.com/questions/21148774/bit-fields-keil-hardfault-after-restarting

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c++

bit-fields

stm32

keil