JTAG debugging with ZPUino?

[tuxadecimal]

Hello,

 

I'm completely new to JTAG and wanted to see if I was on the right track here. I was looking at buying one of these:

http://www.ebay.com/itm/NEW-XILINX-USB-CABLE-DOWNLOADER-PLATFORM-JTAG-DONGLE-/260812659422?pt=LH_DefaultDomain_0&hash=item3cb9a55ade

 

I have a Papilio Pro that I run a (slightly) modified ZPUino on but the core is the same. The main difference is I don't use the UART to program it in the same way ZPUino does, basically I have custom boot loader code.

 

From what I can gather from searching the web and this site it seems easy enough to use IMPACT to program a bit file and it seems I can debug code running on the ZPUino with this as well based on my understanding of how "zpuino_debug_core.vhd" and "zpuino_debug_jtag.vhd" work. So here is where I am at:

 

Solder a header onto the open JTAG slots on the board

Put the FT2232 into High-Z mode (does the second channel used for the UART still work in this case?)

Program an updated bit file that incorporates the zpuino_debug_jtag(this is the TAP, correct?) with IMPACT

 

And then I'm not sure where to go from there, is there a program that will let me use GDB(zpu-elf-gdb) with this configuration to step through code? Is this what OpenOCD does and if so can I use it with the ZPUino core? Is there anything else I need to do this?

 

Any insight would be much appreciated as to how/if you guys are doing this kind of thing. Thank so much.

 

[alvieboy]

Perhaps better we discuss this by email. Can you send me one to alvieboy@alvie.com ?

 

Best,

Alvie