Hello everyone,

I'm trying to implement a digital video transmitter using an Xilinx 3A-DSP FPGA, without success. I have a camera feeding video data into the FPGA, and I want to view and record the video in digital format.

I know that Xilinx have an IP core for DisplayPort (reference information UG696), but it's not for Spartan-3 series FPGAs. There is an Xilinx application note (XAPP460) which discusses how to implement DVI and HDMI in Spartan-3 FPGAs, but I am having trouble setting up my design. Is anyone aware of a core available which will provide a DVI transmitter (source) function? Has anyone done it?

There's an OpenCores project (VGA/LCD Controller) which states that it can provide 12-bit DVI, which would fit my needs - but then it doesn't seem to do it. Is DVI actually possible using the VGA/LCD Controller core?


Thanks,

Ewan

The Spartan 6 is *much* better suited for the purpose you have in mind than Spartan 3 generation. Even the S6 will limit you to 1080i or 1080P30 signaling, 24 bits per pixel (8 bits per R/G/B colour plane).

- Bob Elkind

DisplayPort, DVI, and HDMI are standards for connectors, signal levels, signal timing, protocols, functions, and operational sequences. All three of these refer to related standards (AES/EBU audio, CEA video, I2C, VESA EDID, etc.). Any open source cores you find are unlikely to be a complete solution for what you are trying to accomplish.

My suggestion, if you are committed to this project, is to purchase/download the appropriate specification docs and read through them to understand the scope of your design task.

Another approach is to purchase an off-the-shelf HDMI/DVI/DPort interface controller (Silicon Image is the big dog in this market). You may find that the essential design information you need is protected and limited to paid-up licensees of one or more consortium standards groups (e.g. HDMI).

Hello,

just a quick clarification - I only need to transmit video, so realistically a DVI transmitter core would fit my needs. I mentioned DisplayPort and HDMI in the possibility that someone new of a open core available for those names.


Thanks,

Ewan

Ewan, I'm going to nit-pick you on this.

DVI spec covers connector, electrical, and 8b/10b encoding/decoding -- and not much else.

Are you using DVI strictly as a physical layer interconnect, or are you interested in interoperability with "standard" LCD displays? A standard DVI or HDMI source must support EDID or DDC (defined by VESA).

Are you going to support "standard" video format(s) and timing (defined by VESA and CEA), or are you connecting to a custom-defined/specified display and simply using the DVI interface as a physical transport layer (and nothing more)?

It sounds like you are not interested in embedded digital audio (pun intended).

- Bob

I stand by my earlier suggestion: Spartan 6 is much better suited than Spartan 3 for high-bit-rate serial. Xilinx has provided IP examples for 10:1 serialisers and clock generation for Spartan 6. The serialiser and timebase is critical to the interface. Any old FPGA can manage the pixel level digital encoding and sequencing.

Just a suggestion...

- Bob Elkind

Hi Bob,

thanks for asking the pointed questions - yes, this is for interoperability with standard displays and the video will be of standard format. There's no audio involved, either.

I am looking at the Spartan-6 although cost is a factor - the Spartan 3A DSP FPGAs are much cheaper.

Thanks,

Ewan