GR551X SDK中的XQSPI最大可以支持16MBytes(128Mbit) Flash访问，前8MBytes支持XIP访问，后8MBytes空间需要使用QSPI方式访问，主要原因为XIP CTRL只支持24bit直接寻址。

扩展支持32MBytes Flash访问的Patch见附件，访问地址访问超过16MBytes时，需要配置Status寄存器，该寄存器生效需要ms级别的时间(由Flash Page Program时间决定)，因此>16MBytes地址访问效率会变低。Patch使用方法如下：

1．拷贝附件文件到components\libraries\hal_flash目录并加入项目工程；

2．该套接口只支持地址0x01000000以上的读、擦、写访问；低于0x01000000地址请使用以前的接口，主要API接口如下：

uint32_t hal_flash_read_expand_high_address(uint32_t addr, uint8_t *p_data, uint32_t size);

uint32_t hal_flash_write_expand_high_address(uint32_t addr, uint8_t *p_data, uint32_t size);

bool hal_flash_erase_expand_high_address(uint32_t addr, uint32_t size);

3. 附件提供的Flash操作命令可能不同的Flash型号有差异，以实际Flash规格书定义为准，注意以下几个点：

(1) 读写状态寄存器方法，例如exflash_wait_busy & exflash_wait_addr_mode用到的指令可能有差异，

例如GD25B256D，wait busy用的0x05, addr mode用0x35;

The Read Status Register (RDSR) command is for reading the Status Register. The Status Register may be read atany time, even while a Program, Erase or Write Status Register cycle is in progress. When one of these cycles is in progress,it is recommended to check the Write in Progress (WIP) bit before sending a new command to the device. It is also possibleto read the Status Register continuously. For command code “05H” / “35H” / “15H”, the SO will output Status Register bitsS7~S0 / S15-S8 / S23-S16

(2) Enable/Disable 4Byte地址的指令和流程