After downloading the bit file of the LEDDCD40 project to the XS40-005XL prototype board and using the XSPORT program to input test signals, I encountered a problem. Once the bit file is downloaded, the LED goes blank. I expect that this should be the case. If I wait and don't input a test signal for around 15 seconds after downloading the bit file, the LED suddenly displays the number 3. When I do send a test signal afterwards, the LED correctly decodes my binary input to the corresponding decimal number. If I don't input another test signal in the next 15 seconds, the LED display goes back to the number 3. To verify that this was not just a problem with my bit file, I instead downloaded the pre-compiled bit file from the CD. The same problem occurred as stated above. The computer I am having this problem on is running Win95. The strange thing is that when I tried this on my WinNT system at work, there was no problem. Is this a problem that you have encountered before? Please let me know what you believe may be the cause of this problem and what I can possibly do to solve it.
Do you have some printer port daemon that resets the parallel port every 15 seconds? That would account for this behavior since it would set the 8 data bits to "00000000" and this would display a '3' (due to inverters on the XS Board). What mode is your parallel port in (SPP, ECP, ...)? Is the XS Board the only thing attached to your parallel port?