Category: Configuration/Programming
Tool: Diamond
Device: ECP3, ECP5

Even though it was able to write the first time, if writing fails after the second time, it is possible that the SPI port connected to the SPI-Flash is not enabled and cannot be accessed.

The "MASTER_SPI_PORT" setting in the "Global Preference" tab of Diamond's "SpreadSheet View" is "DISABLE" by default. After programming the generated configuration data (.bit) to SPI-Flash without changing to "ENABLE", once configured with this data, the FPGA's SPI port will not function as "MASTER_SPI_PORT". , after that, writing to SPI-Flash is disabled.

There are two ways to recover if a problem occurs.

[1] Erase the device. "MASTER_SPI_PORT" is "ENABLE" in blank ECP5
[2] After generating configuration data with "MASTER_SPI_PORT" changed to "ENABLE", select "Fast Program" mode in the Programmer to directly configure the FPGA. This will enable the SPI port so you can program to SPI-Flash.