QN9020读串行闪存时，芯片不工作

static void read_flash(uint32_t addr, uint32_t *pBuf, uint32_t nByte)
{
    addr += QN_FLASH_BASE;   //get the data register address of flash control register
    while(is_flash_busy());  //wait the flash is free.
    sf_ctrl_SetDataLen(QN_SF_CTRL, nByte);
    nByte >>= 2;               //nByte must is 4 integer times
    while (nByte--)
    {
        *pBuf++ = *(uint32_t *)addr;
        addr += 4;
    }
}

执行 sf_ctrl_SetDataLen(QN_SF_CTRL, nByte);就会出现芯片不工作，请问是哪里出了问题？

__STATIC_INLINE void sf_ctrl_SetDataLen(QN_SF_CTRL_TypeDef *SF_CTRL, uint32_t value)
{
     __wr_reg((uint32_t)&SF_CTRL->DATA_LEN, value);
}