How to use an EPCS Flash

As I answered you before, I access M25P16 with EPCS controller and I haven't any problem. Your device is similar to mine but support page erase and has different "Device Identification" (80h 15h instead of 20h 15h of mine). You can take a look to datasheet to understand if there are other differences.

I've introduced epcs controller in my design (firmware is located in cfi flash memory) only to support the update of FPGA by means of physical connection different by JTAG (e.g. serial port or ethernet). Epcs controller gives you the possibility to handle (r/w) EPCS memory device from Nios.

I suppose that you have to use epcs controller.

In order to update your firmware (if you placed it within epcs flash) you need epcs controller.

The fastest way to get success in your trouble could be using M25P16. I did'n need to make any modification to HAL driver substituting Altera device with Numonyx one.

BR,

Paolo