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AR# 13360

4.1i Install - Error: "Unable to establish communication..." (Parallel Cable III Driver is not installed)


Keywords: install, Parallel, III, establish, communication, cable, driver, impact, download, JTAG programmer

Urgency: Standard

General Description:
I selected the Parallel III Cable Driver during installation, but a "Cannot establish communication ..." error message appears when I try to program using iMPACT.



In rare cases, the drivers are prevented from being installed on Windows operating systems. A revised driver installation program is available for download at:

To install the drivers, open a command window and execute the file. Then, reboot your computer.

This issue was fixed in the 4.2i PC CD release.


If the Parallel Cable III Driver appears as "installed" in your fileset.txt file, then the driver was installed. You can check System Properties -> Hardware -> Device Manager -> Ports -> Port Settings to verify that you have "Legacy plug-n-play" enabled, and that "Never use an interrupt" is selected. (Please see (Xilinx Answer 10942) for more information on this.)

We also recommend the use of a bidirectional port setting. (Please see (Xilinx Answer 11505) for more information.)


Another possible way to work around the problem is to manually copy the drivers into the correct directory and set the necessary registry entries.

Using Windows Explorer, browse to your <$xilinx>\bin\nt directory to locate the drivers listed below:

Windows NT or 2000

1. Copy "windrvr.sys" to the <windows system>\drivers directory.
2. Launch "Regedit", and set the following registry entries in the key:


"DisplayName" = "WinDriver"
"ErrorControl" = (DWORD) 1
"Group" = "ExtendedBase"
"ImagePath" = "\SystemRoot\System32\drivers\windrvr.sys"
"Start" = (DWORD) 2
"Type" = (DWORD) 1

Windows 98 or ME

1. Copy windrvr.vxd to the <windows system>\vmm32 directory.
2. Launch "Regedit" and set the following registry entries in the key:


"Start" = (DWORD) 0
"StaticVxD" = "*windrvr"


Another way to work around the problem is to install the WebPACK Programming Tools, which are available for download at:


If the machine has both 4.2i ISE and 5.1i Service Pack 2 ISE (or later releases) installed on it, the 4.2i iMPACT version will not be able to communicate with the parallel port after 5.1i Service Pack 2 is installed. (This is due to a driver conflict). This problem does not affect 5.1i Service Pack 2 iMPACT, which will work correctly with both software versions installed on the same machine.

NOTE: The 5.1i iMPACT programming software will accept files that were generated in previous software versions.
AR# 13360
Date Created 12/10/2001
Last Updated 11/05/2003
Status Archive
Type General Article