MT25Q512 Programming Issue When Connected to Cyclone 10CX150Y

Hello friends,

I am trying to program an MT25Q512 QSPI Flash memory that is connected to an Altera Cyclone 10CX150Y FPGA through QSPI CS, CLK, DQ0, DQ1, DQ2, and DQ3.

The Flash memory can be programmed successfully when it is standalone. However, programming fails when it is connected to the FPGA.

During programming, I hold:

• nCE High
• nCONFIG Low

Could you please confirm whether this should force the FPGA QSPI pins into a high-impedance state?

Please advise whether any additional FPGA pin control, board-level isolation, or specific programming sequence is required in order to program the MT25Q512 externally while it remains connected to the FPGA.

Best regards