Wednesday, January 12, 2011

Atlys and HDMI on Linux

Xilinx App Note 495 describes sample implementations of DVI/HDMI receiver and transmitter on the Digilent Atlys board. I built the code using WebPACK 12.4, and it works as advertised: The colorbar test pattern displays nicely on my HDMI monitor.

Also installed Digilent's Linux version of their Adept tools for FPGA programming. They don't seem to have the full GUI version available, but the command-line tool was able to load my test code (as a WebPACK-generated .bit file) into the Atlys FPGA with no problem. Don't see any way to load code into the SPI flash: it appears that Windows-based tools are still needed for that.

Only one minor glitch: I use Debian, which isn't one of Digilent's supported distributions. In recent versions of Debian, the udev package doesn't allow plugin devices to have protection mode 0666, which means that the Digilent tools will only work if run as root.
The fix is to edit "/etc/udev/rules.d/52-digilent-usb.rules" and add a group:
SYSFS{idVendor}=="1443", MODE="666" GROUP="plugdev"
then any user in the "plugdev" group can run the Digilent tools. The /etc/group file should have a line like
plugdev:x:46:jr
where "jr" is my username.

4 comments:

Kaveh said...

Hi Joe,
Have you ever tested hdmi-in hdmi-out on this board? hdmi-out seems working fine with internal pattern generator. But hdmi-in doesn't work for me.
I shorted JP6 and JP7 to connect output I2C to input I2C. Bu my hdmi source still doesn't recognize the display.

Thanks,
Kaveh

Joe Rothweiler said...

Kaveh,
Yes, I was able to get it mostly working. I just created a new blog post (21Feb2011) with more details about my setup. Hope it helps.
Please keep us updated on any progress/problems.
Thanks,
Joe

Chris McClelland said...

You may find FPGALink of interest. It's a cross-platform (i.e Linux, MacOSX, Windows) open-source library for programming an FPGA and subsequently communicating with it over USB. It supports many Digilent boards, including Atlys.

Joe Rothweiler said...

Chris, thanks for the note, FPGALink does look like an interesting project.
Joe R.