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Parallel Cable IV opened in "Compatibility Mode"

Hi folks,

this is starting to drive me nuts:

I use a Xilinx Parallel Cable IV to program some big FPGAs (big as in V2P70 and the like). Now Impact and Chipscope always open this cable in "Compatibility Mode", meaning it is used as a Parallel Cable III and takes FOREVER to download a bitstream. No matter what I do, no matter what settings for the parallel port I use, it keeps getting detected as a Parallel Cable III. This is a problem we've been having constantly for years now... on some machines it works fine, on some it doesn't, and on some others it sometimes works but sometimes doesn't.

The only certain thing is that it never works on the machine I am currently working on when I have a lot of testing to do and big bitfiles to download.

Now, I've googled my eyes out for this, read all the answer records, tried everything mentioned there and everything I could think of:

- I tried all possible BIOS-settings for the parallel port: ECP, EPP, bidirectional, different DMA-channels, different IRQs; you name it, I've tried it

- I tried uninstalling the cable drivers from Xilinx, reinstalling new ones. I tried uninstalling the entire ISE, making sure there's nothing left in the Windows-Drivers-Dir, reinstalling ISE. I've tried every ISE-version from 4.2 to 7.1 without success. I've tried doing a fresh install on a freshly installed Windows, nothing.

Now we bought one of the new platform cables for USB, works much better, but those are expensive and we have probably half a dozen "Parallel Cable IVs" in use.

Any pointers, any hints?

cu, Sean

Reply to
Sean Durkin
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Once we had problems with "Wigglers" for Motorola processors. It pointed out that it was related to cabeling. Use of a good printer cable and keeping the cable between the Wiggler and the development board short solved the problem. I bet you did not change the cables while trying.

Regards, Thomas

Reply to
Thomas Rudloff

Make sure that your board has proper termination on the JTAG lines. Scope the voltages on the JTAG plug and make sure they are stable. Use the mouse PS2 port, not the keyboard one, for the cable power. Make sure you have updated chipset drivers. The odds are that your parallel port controller is made by Intel. I wouldn't run any version of ISE older than 6.2.3. I noticed some fixes in the 6.2 service packs. Make sure the device manager shows that it is using the ECP driver and set it to use an interrupt if one is available, which it should be.

If all of the above appear correct, then recognize the truth: there is no spoon. The fact is that the DMA mode for the parallel IV stuff has never worked worth a crap for me. The impression I got from support when I called about it was that they get an aweful lot of calls on the topic. The fact that they charge $500 for their USB cable is BS. They do that because they have a monopoly on the item and use the frustration caused by their parallel cables to drive the market.

Reply to
Brannon

Hi Sean, Is there also a dongle on the port? Syms.

Reply to
Symon

I had a similar problem. When I switched to an external power supply instead of using a PC PS2 port, the problem went away.

Marc.

Reply to
Marc

Similar comments to Brannon. If you have more than one device in the JTAG chain make sure you have the appropriate pullups on the paths between devices. The Flash devices seem to have enough internal . The V2Pro does not seem to have enough internal pullups on these lines. We have a setup with 4 V2pros in the chain and we missed the pullups (except on the last device to the cable.) We added the pullups and went from 7 min in cable II Compat mode to 20 sec in Cable IV mode. (ECP mode with Int 7 enabled with both)

Reply to
Nitro

I don't think this has anything to do with the actual JTAG-connection. When you start up iMPACT or ChipScope, it opens your cable, and before it even starts scanning your JTAG-Chain, the cable is openend in compatibility mode. You don't even have to hook up the cable to any board at all, the software just detects a cable III on one machine and a cable IV on another.

Plus, why does everything work perfectly with the exact same Parallel Cable, with the exact same board, just by hooking it up to a different PC? And why does it work fine with the USB-cable?

I guess this is just a driver problem....

cu, Sean

Reply to
Sean Durkin

Did some more research on this...

Obviously the ECP port test fails when iMPACT or ChipScope try to open the cable. ChipScope 7.1 is more verbose "Expected 00 but read 20", hence it suspects ECP is not working and uses compatibility mode.

It obviously does not matter what BIOS-Settings or driver settings in Windows you use...

Xilinx uses Windriver from Jungo to talk to the cable, and this is what I found on their website:

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"Parallel / Serial Port Issues

I am using WinDriver for communicating peripherals with the parallel port. In case of ECP mode, some computers work well, but on one computer this does not work. This might be a hardware problem, due to BIOS-specific implementations of parallel port modes on various computers. WinDriver cannot control this behavior, since it is programmed into the BIOS. We advise you to follow the brand of computer or BIOS that you have observed works correctly."

OK, so it's all the BIOS' fault and I'm supposed to only use computer with compatible ones. That is one hell of an elegant solution.

cu, Sean

Reply to
Sean Durkin

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