USB Interrupt In Transfers

Saxo/-L & Xylo/-EM/-L/-LM boards

USB Interrupt In Transfers

Postby bruno » Mon Mar 01, 2010 1:31 am


We received our Xylo-L, and it does look like the hardware guy is having fun. Thank you!

We are planning to connect it via USB to a Technologic TS-7800 SBC running Linux as part of a gamma ray experiment that will fly as a balloon payload.

The Xylo-L will be used to packetize the serial data streams from 32 detectors and forward those packets to the TS-7800.

Ideally we would like to configure EP2 to be an interrupt-in endpoint with quad buffering. The TS-7800 would then have a driver that stored the received data in a ring buffer and supported a non-blocking read of that ring buffer.

This design should provide the Xylo-L with the most frequent opportunity to offload its data while placing the minimum overhead on the TS-7800's CPU.

Given the variety of examples available it seems that developing the above software would be a manageable task, but in an effort not to duplicate other peoples efforts, I would like to ask the following questions:

    1. Is the buffering scheme configurable in the 8051 firmware image provide with the Xylo-L?

    2. Would it be possible to get a firmware image for the 8051 that configures EP2 as described above?

    3. Would it be possible to get the source for the 8051 firmware image provide with the Xylo-L?
      * Either under NDA or with any proprietary code removed.
    4. Would it be possible to get a list of the EZ-USB registers and values that are configured by the Xylo-L firmware?
      * Just the ones that pertain to the non-proprietary configuration.
    5. Does anyone have any other working 8051 firmware and driver code that they would be willing to share?
I would be happy to share any results of this effort that are not restricted by any applicable NDAs.

Thank you,

Bruno Pape
Space Science Center
University of New Hampshire
Durham, NH 03824
    Posts: 5
    Joined: Tue Feb 23, 2010 4:03 pm

    Postby fpga4fun » Mon Mar 01, 2010 5:12 am

    You could take a look at this Saxo's firmware

    The idea being that you use it as a base to reprogram the 8051 and configure the endpoints to your liking.
    Site Admin
    Posts: 837
    Joined: Thu Sep 18, 2003 6:47 am

    Postby bruno » Tue Mar 02, 2010 2:40 pm

    Hi Jean,

    I had been struggling to fully understand Wolfgang's fx2pipe firmware and had not looked at the firmware for the advanced examples, partly due to their descriptions, but the firmware for the advanced examples looks like it will make a very good starting for our work.

    Thank you!

    Posts: 5
    Joined: Tue Feb 23, 2010 4:03 pm

    Return to FX2 FPGA boards