神秘的内存写保护

Question

我正在 ATSAME51N20A (Cortex-M4) 上实现串行引导加载程序。我正在通过 UART 读取数据包，并将它们写入内部闪存。对于某些内存地址，闪存写入工作正常，而对于其他地址则根本不起作用。

Here 是数据表。我已经检查了我能找到的所有寄存器配置，一切似乎都没有问题。

这是我的初始化代码：

void init(void)
{
     GPIOInit();
     USARTInit();

     NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_AUTOWS | NVMCTRL_CTRLA_WMODE_AP | NVMCTRL_CTRLA_PRM_MANUAL;
     hri_mclk_set_AHBMASK_NVMCTRL_bit(MCLK);
     hri_mclk_set_APBBMASK_NVMCTRL_bit(MCLK);

     PAC->WRCTRL.reg = PAC_WRCTRL_PERID(ID_DSU) | PAC_WRCTRL_KEY_CLR;
     MCLK->AHBMASK.reg |= MCLK_AHBMASK_DSU;
     MCLK->APBBMASK.reg |= MCLK_APBBMASK_DSU;
}

这是我写的flash代码：


#define APPLICATION_START_ADDRESS 0x8000
#define PAGE_SIZE (512U)

void NVMErasePage(uint32_t pageOffset)
{
    // Set the NVM page address that we want to erase
    NVMCTRL->ADDR.reg = (APPLICATION_START_ADDRESS + (pageOffset * PAGE_SIZE));

    // Wait until the NVM controller is ready
    while (0 == NVMCTRL->STATUS.bit.READY);

    // Lock region size is always bigger than the row size
    NVMCTRL->CTRLB.reg = NVMCTRL_CTRLB_CMDEX_KEY | NVMCTRL_CTRLB_CMD_UR;

    while (0 == NVMCTRL->STATUS.bit.READY); // Unlocking is a fast operation

    // Erase the page that contains our address
    NVMCTRL->CTRLB.reg = NVMCTRL_CTRLB_CMDEX_KEY | NVMCTRL_CTRLB_CMD_EP;

    // Wait until the NVM controller is ready
    while (0 == NVMCTRL->STATUS.bit.READY);
}

void programApplicationFlashPage(uint32_t pageOffset)
{
    uint32_t *flash_buf = (uint32_t *) (APPLICATION_START_ADDRESS + (pageOffset * PAGE_SIZE));
    for (int i = 0; i < PAGE_SIZE/4; i++)
    {
        flash_buf[i] = *(uint32_t *) (memoryLocation + (i));
    }
    while (0 == NVMCTRL->STATUS.bit.READY);
}

我可以从地址 0x1A00 到 0x1E080（偏移量 145-175）写入闪存页面，但在此之前和之后，应该写入的内存不会改变。

根据数据表，RUNLOCK 负责 NVM 的写保护，我验证了它被设置为解锁所有 NVM 扇区 (0xFFFFFFFF)。

还有什么可以阻止我写入所有 NVM？

编辑

添加了擦除闪存并在 flash/write 操作后等待的代码。我看到闪存全部被擦除（所有位都设置为高），但写操作不起作用。

Answer 1

想通了。我发出的是擦除页面命令而不是擦除块命令。擦除页仅适用于闪存中的用户数据页，而不适用于主闪存组。

这是对我有用的代码：

if((flash_addr % BLOCK_SIZE) == 0)
{
    // Set the NVM block address that we want to erase
    NVMCTRL->ADDR.reg = blockAddress;

    // Unlock the region that contains our address
    NVMCTRL->CTRLB.reg = NVMCTRL_CTRLB_CMDEX_KEY | NVMCTRL_CTRLB_CMD_UR;

    // Wait until the NVM controller is ready
    while (0 == NVMCTRL->STATUS.bit.READY);

    // Erase the block that contains our address
    NVMCTRL->CTRLB.reg = NVMCTRL_CTRLB_CMDEX_KEY | NVMCTRL_CTRLB_CMD_EB;

    // Wait until the NVM controller is ready
    while (0 == NVMCTRL->STATUS.bit.READY);
}

for (int i = 0; i < PAGE_SIZE /4; i++)
{
    flash_buf[i] = *(uint32_t *) (memoryLocation + (i));
}
while (0 == NVMCTRL->STATUS.bit.READY);

神秘的内存写保护

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c

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cortex-m