Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

IDE, Serial Loader programming problems

We are using this board:

Custom board with EP2C8 device and EPCS16 serial loader

Micron 16 meg SDRAM

VGA output with custom verilog controller which uses SDRAM for VRAM

EPCS controller, JTAG uart, system ID, timer, etc.

We made up a complete system for it and programmed it successfully. Then we loaded that system into the serial loader. VGA comes up with random SDRAM data for pixels.

1) We tried making a Nios II IDE project for our working system. Compiled fine, and upon running it gave us this error:

Using cable "USB-Blaster [USB-0]", device 1, instance 0x00

Pausing target processor: not responding.

Resetting and trying again: FAILED

Leaving target processor paused

2) We read this post on the forum describing a similar problem (http://forum.niosforum.com/forum/index.php?showtopic=3283), and it suggested that their DDR core was the culprit. We tried creating a new project without it (and consequently without the VGA controller), and found upon normal JTAG programming that the system was left unchanged (i.e. VGA turns on). I didn't actually try running hello world on the system without the SDRAM, because we figured it was unchanged. I might try that as my next step.

3) We then assumed that the cause of problem# 2 was that it was being reprogrammed with the prior system in our serial loader. We tried erasing and reprogramming the serial loader, and we get this error in quartus:

Error: Flash Loader IP not loaded on device 1

Error: Unexpected error in JTAG server -- error code 44

Error: Operation failed

In summary, we can't run code on our system, we can't change our system because it's defaulting to the serial loader contents, and we can't erase the serial loader.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Hi Rhaik,

    are you using serial resistors on your jtag signals?

    We had to add 47 Ohm serial resistors to the jtag signals on one of our custom boards in order to get the jtag interface to work properly.

    --wolfgang
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    --- Quote Start ---

    originally posted by pfab@Feb 20 2006, 01:39 AM

    hi rhaik,

    are you using serial resistors on your jtag signals?

    we had to add 47 ohm serial resistors to the jtag signals on one of our custom boards in order to get the jtag interface to work properly.

    --wolfgang

    <div align='right'><{post_snapback}> (index.php?act=findpost&pid=12816)

    --- quote end ---

    --- Quote End ---

    Well, we tested this with the ByteBlaster II, which has slower JTAG signals than the USB Blaster, and it worked. We therefore think that we have some speed issues with the JTAG, and the hardware guy thinks we might be able to fix it by adding caps.

    Anyway, so now that our JTAG works OK, we narrowed down the cause of the running code problem.

    Our SDRAM isn&#39;t working right. I&#39;m going to take the discussion over to this thread (http://forum.niosforum.com/forum/index.php?showtopic=3283).