How do I use N25Q512 Quad-SPI Flash, instead of ECPQ512?

We use N25Q512A as configuration flash for Cyclone V in one of our projects and got the same problem. Finally, I've got it working. N25Q512A have almost the same command set, as epcq devices, but there is one exception. One should execute READ FLAG STATUS REGISTER command before every PAGE PROGRAM or ERASE commands. Thats why Altera Programmer can't write anything to this chip. But you can write firmware to flash manually using NIOS with epcs flash controller ip core. You should use *.rpd programming file with big endian endianless (button "Options/Boot info..." in Convert Programming File dialog). Here is NIOS C example code in attachement.