Channel Link Evaluation Kit User Manual
National Semiconductor Corporation
Interface Products
LIT# CLINK3V28BT-85-UM
Rev 2.1
Date: 10/12/2005
Page 19 of 28
Troubleshooting
If the demo boards are not performing properly, use the following as a guide for
quick solutions to potential problems. If the problem persists, please contact the
Interface Applications hotline number (+1 408 721 8500) for assistance.
QUICK CHECKS:
1. Check that Power and Ground are connected to both Tx AND Rx boards.
2. Check the supply voltage (typical 3.3V) and also current draw with both Tx and
Rx boards (should be about 200mA with clock and one data bit at 66MHz).
3. Verify input clock and input data signals meet requirements (VIL, VIH, tset,
thold), Also verify that data is strobed on the rising edge of the clock.
4. Check that the Jumpers are set correctly.
5. Check that the 2 meter cable is properly connected.
TROUBLESHOOTING CHART
Problem…
Solution…
There is only the output clock.
There is no output data.
Make sure the data is applied to the correct input pin.
Make sure data is valid at the input.
No output data and clock.
Make sure Power is on. Input data and clock are
active and connected correctly.
Make sure that the 2 meter cable is secured to both
demo boards.
Power, ground, input data and
input clock are connected
correctly, but no outputs.
Check the Power Down pins of both boards and
make sure that the devices are enabled (/PD=Vcc) for
operation.
The devices are pulling more
than 1A of current.
Check for shorts in the cables connecting the TX and
RX boards.
After powering up the demo
boards, the power supply
reads less than 3V when it is
set to 3.3V.
Use a larger power supply that will provide enough
current for the demo boards, a 500mA power supply
is recommended.
