To program my Atmel(ATmega128L) controller and Xilinx FPGA (sparta-3 XCS400) at the same time, I decided as a programmer to use the Xilinx Parallel Cable III. I implemented the programmer 100% the same as found in Xilinx's website (The programmer worked, but not without problems. For programming the Atmel uC I used AVRdude, and for the FPGA, ISE9.1i. The ribbon-cable from the LPT port to Programmer was 20cm long and from the programmer to the uC/FPGA board was not more than 10 cm. The problem related with this programmer were verification errors, i.e the PC can't program or read properly from the board. The interesting thing is how these verification problem came up. In the morning when I turn the PC and Board on, these verification errors are a lot. When the code that I want to download is big, its impossible to program the FPGA/uC, for small codes it works but after many tries. After 10 tries or so, the programming works correct and no verification errors no matter how many times I try to download the code or how big the code is, and this without even touching a thing on the hardware!!!
Since this problem applies to more than one board, I assume the problem must lay on the programmer itself. My explanation is that maybe the buffer IC's get hot or something...I really don't know. I want to know if there is anyone who has had problems with this programmer cable.
Thank You, JJ