Resolved! Stm32l4r9 octospi mode is configured as Quad SPI and memory mapping is enabled, but it cannot be accessed by address. Once the address of 0x90000000 is read, MCU will make hardware error??
1. It is correct to read and write flash through command function when there is no memory mapping enabled( flash:MX25R6435F )2. After memory mapping is enabled, after accessing the address of 0x90000000, the MCU crashes and cannot recognize the chip....