Digilent X-Board User Manual
Page 6
Digilent
X-Board Reference Manual
www.digilentinc.com
Copyright Digilent, Inc.
Page 6/6
Doc: 502-107
Upcoming features
New designs are being developed that will allow the user to transfer data into the CPLD from a
Windows interface, as well as utilize the microprocessor embedded in the EZ-USB chip. Please return
to the Digilent website for the latest updates.
CoolRunner-II CPLDs support JEDEC readback as well as a signature setting, which are not
supported by ExPort at the time of initial release. These features will be added in future versions of
the ExPort software. If this functionality is needed, you will need to purchase a programming cable
and use the Xilinx iMPACT programming software.
Troubleshooting
Q: ExPort does not recognize the device when I click ‘Initialize Chain’.
A:
- Ensure that SW1 is set to the PROG and not MTR.
- Re-connect both ends of the USB cable.
- Ensure that X-Meter is not running. It shares the USB driver and will conflict with ExPort.
- Verify that WebPACK is installed and the XILINX environment variable is set properly.
o
The environment variable can be found by right-clicking
My Computer Æ Properties Æ Advanced tab Æ Environment Variables
o
Verify that the XILINX system variable has the correct installation location.
Q: X-Meter shows ‘Unable to connect to SPI device’ message.
A:
- Ensure that SW1 is set to MTR.
- Disconnect, and re-connect the USB cable
- Re-install the Adept software suite.
Q: X-Meter shows ‘overflow’ for the Current consumption.
A: Change SW1 to from PRG to MTR. This toggles between the two modes of operation,
programming and current measurement.
Q: BTN0 and BTN1 do not seem to function. They always seem stuck at ‘1’.
A: Check the termination setting for the CPLD software. If you have inputs set with an internal pull-up,
this will conflict with the external pull-down for the pushbuttons. Either remove the pull-up termination
or change to Keeper.
Q: Power seems a little higher than I would expect. What could cause this?
A: Set the Unused I/O Termination style to GROUND. This disables the 48 MHz clock present on P30.
Q: Why is the power reported by X-Meter as high as 2 mA when the CPLD is erased?
A: This is due to the free-running 48 MHz clock on P30. It can only be disabled by shorting it to
ground.
For additional technical assistance, contact Digilent via email at: