tested an MT25QL NOR flash using STM32CubeProgrammer and an external loader.On the STM32 eval board (same MCU + same flash), read/write/erase works perfectly.On my custom board (same schematic and connections verified), I see an issue:Only alternate bytes are written/read correctlyThe missing bytes always read as 0x99Example:Writing a string → only every alternate byte is valid, others = 0x99

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Question

qspi issue with MT25QL

tested an MT25QL NOR flash using STM32CubeProgrammer and an external loader.

On the STM32 eval board (same MCU + same flash), read/write/erase works perfectly.
On my custom board (same schematic and connections verified), I see an issue:

Only alternate bytes are written/read correctly
The missing bytes always read as 0x99

Example:
Writing a string → only every alternate byte is valid, others = 0x99

Technical Moderator

Hello @sravanemedge and welcome to the community;

I recommend you to test an available example like as QSPI_MemoryMapped and use a logic analyzer or oscillator to verify data line activity.

Thank you.

Kaouthar

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