Hello
It is possible to use inexpensive ARM JTAG cables (compatible with AMONTEC) with Advanced Debug System. They are based on FT2232 chip and require a minor modification in the code. We have described the details (including patch) on our blog:

http://antmicro.com/blog/2011/08/support-for-amontec-compatible-jtag-cables-in-advanced-debug-system/

For or_debug_proxy it is even more simple. The signal JTAG_OE_N is already supported, so one might only need to alter VID / PID settings to match the cable. The easiest way to do it is to add following lines to src/linux_usb_driver_calls.c

ftStatus = FT_SetVIDPID(0x0403, 0xCFF8);

if(ftStatus != FT_OK) {
printf("Error: FT_SetVIDPID(%d)\n", (int) ftStatus);
return 1;
}

Those lines should be placed in init_usb_jtag() function, right above the line:

ftStatus = FT_ListDevices(pcBufLD, &iNumDevs, FT_LIST_ALL | FT_OPEN_BY_DESCRIPTION);

I hope it helps (especially those condemned to the DLC9 cable).

Hello skrzyp,

very nice. would you like/mind to publish/link this information in our wiki, link below?

http://minsoc.wikaba.com/advanced_jtag_bridge_faq

Greetings,
Raul

Hello

Done ;)
I have posted a recipe instead of a patch, so that it works over updates.

btw. Maybe that line could be enabled out of the box? I have noticed that or_debug_proxy drives that line by default.

I have no objection to that, assuming it doesn't break support for the ORSoC cable. I'm assuming that or_debug_proxy is carefully written to support the ORSoC cable. So, if you can point me to the part of the or_debug_proxy code where that bit is set, and I can verify how it works, I'll make the change to adv_jtag_bridge.

To be sure it doesn't break compatibility, we need to know what is the ADBUS4 line connected to, in ORSoC cable.
I can't find any schematics of that cable, I guess it is some kind of a secret.

What I do know however, is that or_debug_proxy was WORKING with my cable out of the box (except VID/PID issue).
My cable doesn't work if that line is not driven.
So my assumption is that or_debug_proxy actually drives this line.

The schematic is in no way a secret. Attached PDF should describe the cable internals

/Michael Unneback
ORSoC

Thank you Michael!

Looks like ADBUS4 line is floating. Driving it low will not break the compatibility. It would enable family of AMONTEC cables.

I've checked in changes to adv_jtag_bridge to drive the ADBUS4 line low, after looking at the ORSoC cable schematic I agree it shouldn't break compatibility. I've also made the VID and PID of the USB cable command-line options, so users won't have to change code and re-compile. Let me know if this works with your cable...

Hello
It is working perfectly well, great job!