Cheap FPGA for HDMI 2.0 4k reception? - Page 1
Forum section: electronics / general

author: nctnico
author_rank: Super Contributor
timestamp: September 16, 2023, 09:30:40 am
content: For an upcoming project I could use a cheap FPGA that can receive HDMI 2.0 (or better) at 4k 60Hz to create an HDMI to LVDS converter (*). I have found some articles about FPGA vendors claiming to be able to receive HDMI but I have not spotted any parts. I don't need sound or content protection and I have full control over the source. Any suggestions?* I know there are chips which can do this but these look like boutique parts that could be hard to source long term.

author: asmi
author_rank: Super Contributor
timestamp: September 17, 2023, 01:59:51 am
content: HDMI 2.0 requires 6 Gbps per lane, so just about any Artix-7 device with speed grade 2 or 3 will do it. You will need an external level shifter. How "cheap" will it be depends on where you buy it, and what kind of density you require. Also read the datasheet carefully as not all packages bond out transceivers.

author: nctnico
author_rank: Super Contributor
timestamp: September 18, 2023, 09:21:18 am
content: Thanks. Those are still rather expensive. Too expensive to replace an HDMI to LVDS board you can buy from China for a few dollars. I also looked at Efinix (Ti90) but those are expensive as well. I'm still hoping there is an FPGA out there with HDMI implemented as a hard-IP block. Gowin makes some mention about it but I have not been able to track down which device has this.

author: asmi
author_rank: Super Contributor
timestamp: September 18, 2023, 02:22:40 pm
content: Quote from: nctnico on September 18, 2023, 09:21:18 amFPGA solution is always going to be more expensive than a specialized hard silicon device.Quote from: nctnico on September 18, 2023, 09:21:18 amNot gonna happen, it's way too specialized and will become obsolete by the time it reaches the market. This is why FPGAs come with generic transceivers which can be used to implement a multitude of different protocols, including those which didn't even exist at a time FPGA design was taped out to manufacturing, as opposed to hard IPs.

author: Scrts
author_rank: Frequent Contributor
timestamp: September 18, 2023, 03:19:42 pm
content: What type of LVDS is expected here? One twisted pair? It will be needed to drive a display or to route the data to some other location using a cable and then "deserialized" to HDMI again?

author: nctnico
author_rank: Super Contributor
timestamp: September 18, 2023, 03:41:09 pm
content: Quote from: Scrts on September 18, 2023, 03:19:42 pmNo. The end goal is to drive a 4k TFT panel. 4k@60Hz will require 4x4 (=16 lanes + 4 clock lanes) of LVDS at least. The SoC I like to use can only output 4k on HDMI. On Mipi-DSI it is limited to full-HD (1920x1080).

author: asmi
author_rank: Super Contributor
timestamp: September 18, 2023, 04:28:30 pm
content: Quote from: nctnico on September 18, 2023, 03:41:09 pmSo you have a 4k panel which is driven by LVDS? That's interesting to know, as all 4k panels I've came across are usually driven by eDP or DSI. eDP is most common in laptops and tablets, while DSI is used extensively in smartphones.

author: Scrts
author_rank: Frequent Contributor
timestamp: September 18, 2023, 05:54:50 pm
content: Quote from: nctnico on September 18, 2023, 03:41:09 pmIt's a specific panel? Or you are basically looking to redesign a 4k TV? Just use a TV...

author: sd
author_rank: Unknown
timestamp: September 18, 2023, 06:42:24 pm
content: I have never seen a 4K panel with LVDS interface. Usually the maximum is 1080p for dual channel LVDS and 1440P for quad channel (which are rare). Are you sure your panel isn't eDP/DSI or V-By-One?

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 18, 2023, 08:35:30 pm
content: Quote from: nctnico on September 18, 2023, 09:21:18 amIf you find one worth just a couple dollars that can support HDMI in 4K let us know. Unless we have all missed the ultimate gem, chances are either you won't find anything like that, or that'll be a pretty niche chip with not much guarantee in terms of support and supply.Quote from: sd on September 18, 2023, 06:42:24 pmSame thought, it sounds unusual, but possibly industrial-type panels, for which LVDS is still rather common.

author: nctnico
author_rank: Super Contributor
timestamp: September 18, 2023, 10:42:49 pm
content: Quote from: sd on September 18, 2023, 06:42:24 pmThat is a good one, thanks for bringing that up. Typically I don't bother with panel selection. The 4k spec is from the customer (which has standarised at LVDS so far) but it looks like all of the 4k industrial panels use V-by-one links indeed. But maybe they manage to source an LVDS one. The LVDS clock would be roughly around 140MHz.

author: asmi
author_rank: Super Contributor
timestamp: September 18, 2023, 11:14:28 pm
content: Quote from: nctnico on September 18, 2023, 10:42:49 pmIf you can influence the panel selection, I'd recommend to push for one driven by eDP, as it's ubiquitous everywhere.