Hi everybody,
I recently bought a Xilinx Spartan-3E evaluation board, which comes with an integrated Platform Cable USB. Looking for a Linux compatible solution to program the FPGA, I found out that Impact requires the binary kernel driver Jungo and is thus not an option.
As Xilinx decided to classify the cable USB protocol specifications as "highly confidential", I started to reverse engineer the programmer to see if I could write an open-source host software.
The programmer is made of a USB microcontroller (Cypress EZ-USB) and a CPLD. After trying to understand the protocol from USB traces only without success, I decided to disassemble the microcontroller firmware. The code gave me more information regarding the protocol, but some USB commands are forwarded to the CPLD through register read/write operations and/or general purpose I/Os.
Not being able to understand the protocol, I thought I would write a replacement firmware which would not require a kernel driver. I'm looking for people interested in the project (or for people who have managed to understand the Xilinx USB protocol :-)). I can take care of the Cypress EZ-USB microcontroller, but needs someone with CPLD programming experience to write a replacement for the Xilinx CPLD firmware.
Laurent Pinchart