Hi ,
We are working on configuring an ISSI Octal Flash memory in DTR mode on the STM32U5 platform and would like your assistance.
We successfully executed the example provided for Macronix in document an5050 example (II. Octo-SPI FLASH in Regular-command protocol example ) flash to enable DTR mode and were able to perform both read and write operations. However, while trying to replicate the same for the ISSI chip that we have interfaced with STM32U5A9J-DK , we modified the instructions, dummy cycles, and address configurations based on the ISSI datasheet.
Here is the sequence we followed to configure the ISSI flash for DTR mode:
Configure 4-byte address mode:
We wrote to the volatile configuration register at address 0x05 to enable 4-byte addressing.Enable Octal DTR mode:
We configured the flash for Octal DDR mode by writing the value 0xE7 to the volatile configuration register at address 0x00.Verify DTR mode:
We read back the volatile configuration register at address 0x00 in DTR mode, and the value was correctly returned as 0xE7.
Issue:
- After step 2 (writing 0xE7 to address 0x00), we are unable to:
- Read any other volatile configuration register addresses,
- Access device IDs, or
- Read from any flash memory addresses in DTR mode.
- Additionally, after writing 0xE7 to address 0x00, the ISSI flash becomes inaccessible in SDR mode, which leads us to believe that it has switched to DTR mode.
Request for Assistance:
- Are we missing any specific steps or sequences required to fully configure the ISSI flash in DTR mode?
- Is there any additional initialization required after enabling DTR mode for the ISSI chip?
- If possible, could you share any documentation or examples demonstrating how to configure ISSI flash for DTR mode on STM32 platforms?
In the post https://community.st.com/t5/stm32-mcus/how-to-set-up-the-ospi-peripheral-to-interface-with-the/ta-p/49474
At last there is a snippet available to configure the ISSI flash in DTR mode , Can you provide us any example code for the same .
Your guidance and insights will be highly valuable for us. Please let us know if you need any additional information regarding our setup or configurations.
Thank you in advance for your support!
