Problem (re-)programming EPCQ16A with NIOS design - Problem (re-)programming EPCQ16A with NIOS design I am not able to program an EPCQ16A with an NIOS based design. Works OK with non-NIOS design until a NIOS deisgn is used. Once the NIOS design is downloaded the PROM appears locked. It can no longer be successfully erased or programmed. I have tried erasing without a design file being specified (to clear all locations). NIOS design will operate if loaded in the FPGA using a JTAG link. Same thing happens on serveral different boards. The EPCQ16A is returning an ID of 0x14, where I was expecting 0x15 according to the datasheet. Hardware: Cyclone IV (EP4CE22) and EPCQ16A. IDE: Quartus Prime 18.1.0 Lite Edition. Programmer: Terasic USB Blaster. The EPCQ16A connected directly to Blaster (non-JTAG). I am guessing that the problem I am seeing may have something to do with the NVCR register in PROM. Any information/experience that can be shared to overcome this problem would be greatly appreciated. Darryl Replies: Re: Problem (re-)programming EPCQ16A with NIOS design Problem resolved: Issue due to 'Use enhanced mode serial flash loader for factory default helper image' being selected in the programmer options.