EPCS16 and problems

[Altera_Forum]

Hi guys. 

I met a problem.As i understand, I am not first person,which has same problems. Lets go. When i try to program flash memory(Altera EPSC16N) by HW and for this purpose i have .jic file, everything is going perfectly. Then (after board restart) if i want to check some Nios2 code by Debug - again everything is perfect. But when i try to program flash(EPCS) by Nios image - here problems are starting.I am trying to program by nios2-flash-programmer-gui. In my application, reset-vector points to epcs_flash_controller_0. When i program flash, i receive following output:  EPCS signature is 0xFF EPCS device doesn't support RDID command No EPCS layout data - looking for section[EPCS-FF] Unable to use EPCS device Leaving target processor paused Error Code: 8 for command ...  I added nios2-flash-override.txt file and i receive same result. I even changed epcs component.  It looks, like programmer cannot read correct sugnature. I also have other board with EPCS4N flash memory.In this memory everything is perfect.  Plz,help guys. It is urgent.  Thank you, Slava.

[Altera_Forum]

I want to continue on this old thread but adding new conditions for the same error. 

I'm getting exactly the same error: No EPCS layout data - looking for section[EPCS-FF] Unable to use EPCS device Leaving target processor paused Error Code: 8 for command ...  But a singularity is that I'm only getting it when programming a certain system. So it should be an error in the description (Qsys). The only difference between this system is that I added SDRAM, but it works when running on Nios II HW so I'm guessing SDRAM is not the problem, or is it?.  *Should I use a tri-state?

[Altera_Forum]

I am having the same issue with an EPCS64N. I have two boards running identical .sof loads - one works and returns this from nios2-flash-programmer: 

 Looking for EPCS registers at address 0x30000400 (with 32bit alignment)  Initial values: 00000000 00000000 00000260 00000000 00000000 00000001  Valid registers found epcs signature is 0x16 EPCS identifier is 0x202017 Using EPCS size information from section [EPCS-202017] Device size is 8MByte (64Mbit) Erase regions are:  offset 0: 128 x 64K EPCS status is 0x00   The other fails and returns this:   Looking for EPCS registers at address 0x30000400 (with 32bit alignment)  Initial values: 00000000 00000000 00000260 00000000 00000000 00000001  Valid registers found epcs signature is 0xff EPCS device doesn't support RDID command No EPCS layout data - looking for section [EPCS-FF] Unable to use EPCS device Leaving target processor paused  Does anybody know why an identical (in theory) circuit and device would return a signature of 0xFF? I have replaced the EPCS64N - same result. I checked the DCLK, DATA, nCS, and ASDI signals with a scope and all look good and similar between boards. Are there bad devices floating around? (These were purchased from DigiKey - an authorized Altera distributor.)

[Altera_Forum]

It appears that my problem is an open circuit between the EPCS and the FPGA on DATA0. I will update this post if that is found not to be the fault.