Simple Nios II DK programming question

Altera_Forum · ‎12-19-2006

I'm just getting started with my new Nios II Developer's kit (Cyclone II edition). I'm trying to program a trivial design into the board just to make sure that I can download correctly.

The design is about as simple as it gets; I'm using two switchs as inputs, and output the AND of those two inputs to an LED.

I compile and download with no obvious problems, but immediately after the download the system resets into the default factory configuration (flashing LEDs, etc).

The question is; how can I download a design directly to the FPGA without the factory design being reloaded immediately after the download finishes?

Thanks,

Steve

Altera_Forum · ‎12-19-2006

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originally posted by sglow@Dec 19 2006, 04:30 PM

i'm just getting started with my new nios ii developer's kit (cyclone ii edition). i'm trying to program a trivial design into the board just to make sure that i can download correctly.

the design is about as simple as it gets; i'm using two switchs as inputs, and output the and of those two inputs to an led.

i compile and download with no obvious problems, but immediately after the download the system resets into the default factory configuration (flashing leds, etc).

the question is; how can i download a design directly to the fpga without the factory design being reloaded immediately after the download finishes?

thanks,

steve

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Not sure why your board would reset. Perhaps you have invalid pin assignments to your output LEDs? Have you loaded an existing quartus project file that assigns the pins according the the specifics of your dev kit?

I am assuming you are using JTAG to download. For my system it just downloads and starts working. If you are talking about powering up and having your configuration run, you will need to program your board in AS mode to write the data into the EPCS chip. This requires converting the .SOF file to a .POF file under the FILE->Convert programming files of the quartus menu, and setting the correct EPCS chip in the configuration device box. On my board I have a RUN/PROG switch. RUN=JTAG download, power up from EPCS. PROG = AS Mode programming. Then use the quartus programmer to program in AS mode and select the file you created. Upon power-up, your device will be programmed with your program now instead of the factory default. (Reset your Run/Program switch back to run before repowering.)

Don't know if this helps as this is pretty basic information, but it looks like you are really starting from scratch. I suggest reading until you are blue in the face, and going through all tutorials first before you try your own "simple" test. It all eventually becomes clear, although it seems you have done nothing for days. I just started myself about a month ago.

Hope this helps.

Nails.

Altera_Forum · ‎12-19-2006

Hi Nails;

Thanks for the response.

I found the problem, pretty simple as you suspected.

It turns out that on this DK board there is an output pin from the FPGA which is connected to the CPLD which handles configuration. When this FPGA output goes low, it causes the board to be reset.

I hadn't bothered to assign anything to this pin, so it was tri-stated. The CPLD must have seen this as a low and immediately caused the board to reset.

Once I realized that this pin existed, it was easy enough to force it high. Now things are working as expected.

Rgds,

Steve