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ULINK USB Interface

The Keil ULINK USB-OCDS Adapter connects your PC USB port to the OCDS pins of the C16x or XC16x hardware. Your hardware must have an OCDS connector to use ULINK.

The Keil ULINK Adapter is a standard USB device that works on Windows computers. If you have problems, check the following list.

To solve communication problems with ULINK...

When the ULINK Device is connected the Power LED must be ON. After a setup and startup period, also the COM LED and RUN LED will be ON for about 1 second. This verifies that the device is correctly connected and recognized by the PC.

If this fails, right click on My Computer and select Properties to open the System Properties dialog. Under Hardware - Device Manager... you can check the status of all connected USB devices. Click on Universal Serial Bus controllers - Keil ULINK to open the Keil ULINK Properties dialog. This dialog page displays the status of the USB device.

To re-install the ULINK USB Driver...

If this driver does not work as shown above, reinstall the Keil ULINK Driver using the following steps.

  1. Login to your computer as an administrator. This is required to make registry changes on Windows 2000/XP.
  2. Delete all *.INF files containing USB\VID_c251.
    1. Use Start - Search - For Files or Folders. Specify *.INF as the file name, VID_C251 as the search text, and the base folder of your operating system as the search location (typically, this is C:\WINNT\ for Windows 2000 and XP computers).
    2. Start Search should present a list of INF files (like KeilUL.INF and and OEM4.INF). Delete these files.
    3. Windows 2000 and XP create pre-compiled setup information files that have the same name but with a *.PNF extension (like KeilUL.PNF and OEM4.PNF). You must delete these files, also.
  3. Delete KeilUL.SYS and KeilUL0.SYS from the C:\WINNT\System32\Drivers or C:\WINNT\System32\Drivers folder.
  4. On Windows 2000 and XP use RegEdt32 to remove all registry entries with USB Vid_c251.
    1. Run RegEdt32 (not RegEdit) from the start menu.
    2. Select HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\USB.
    3. Delete the folder with Vid_251. You may need to change access rights under Security - Permissions to do that.
  5. Reboot your computer.
  6. Update the Keil PK166 software.

Now the Keil ULINK Adapter drivers are completely uninstalled. If you plug in the Keil ULINK again the Windows computer will show a Detect New Hardware.  If this message is followed by the Found New Hardware Wizard dialog select: 

  • Install Hardware Device Drivers - Search for a suitable driver for my device.
  • Locate Driver Files - Specify a location. Select the file KeilUL.INF for the Keil ULINK Adapter. This file can be found on a Keil Development Tools CD-ROM in the folder Keil\Setup\Driver\Drivers.
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