User Programmable Standards Converter

[`FRANK.C]

Having enough memory on the FPGA would be a great solution. At the same time I would like to avoid development boards if I can but wont rule anything out.
I had a look at the cyclone IV E FPGA's the EP4CE115 has 3,888 Kbits of memory.
There are development boards available for it.

Digi-Key at 675 euro
AliExpress at 75 euro

Frank

[Freya]

Ouch, those prices are miles apart

[ppppenguin]

Which suggests there's something possibly fishy about the AliExpress one.

Don't rule out development boards. Modern FPGAs are a bit too complex and need too much support for most people to do development from scratch. I've done it from scratch since the early 1990s and have the scars to prove it. I would never do it again, either professionally or for my own purposes. For the odd one or two units then dev boards like the Arty are cheap enough. If you're going into production then you copy the relevant bits of the dev board design and layout as a first step. All newer FPGAs are in ball grid packages so DIY assembly is difficult. It can be done, google "bga prototype assembly" and you'll get a lot of hits. There's also the shed load of decouplers that need to be fitted to the other side of the PCB behind the chip. So even for small numbers I'd use a dev board for development and pay for manufacture if there's quantity involved. Possible halfway house like the original Hedghog is small FPGA dev board piggybacked on your own PCB. No different in principle to whacking a Raspberry Pi or other SBC on your own main PCB.

I know it means learning new dev tools but the Arty looks like the sweet spot for DIY. It's available through legit channels at a fair price. VHDL stays the same so a lot of things don't have to be re-learned when switching from Altera to Xilinx.

If the FPGA has dedicated CPU cores or can readily support them it's possible (though I'd be as much of a beginner as Frank) to have your MPU in the FPGA. Some dev boards have all of this built in. Haven't looked carefully at Arty for this. Then you can control the whole thing over ethernet from a PCat first. Then fit a physical front panel later if wanted.

[Nick]

Have you looked at the Digilent kits? I use their Basys3 boards in some projects and have one of their Analog Discovery IIs - all good stuff...

[jjl]

I hadn't thought about FPGAs with enough memory for a framestore. A frame of video, 720x576, is 414720 pixels. For monochrome that would be the same number of bytes or 3317760 bits.

In theory it would help, but a FPGA with enough block RAM for a framestore may not come cheap. For example the largest Spartan 7 device (lowest cost range from Xilinx) you would need the largest in the series, the XC7S100:
https://www.xilinx.com/support/documenta...ide.pdf#S7

In the Artix 7 (next lowest cost) the XC7A75T would have enough BRAM. The Arty development board is available with the 7A100 device at $250: https://store.digilentinc.com/arty-a7-ar...hobbyists/

I haven't looked up similar for Altera. Which is the Kintex development board you're looking at? I though that Kintex and low cost were mutually exclusive.

Jeffrey

I was mistaken, the board I was think of was the Digilent Basys 3 that features an Artix-7. Details are here https://store.digilentinc.com/basys-3-ar...ory-users/

This board https://store.digilentinc.com/cmod-a7-br...ga-module/ might be more appropriate for the sort of project that Frank and you are contemplating.

John

[`FRANK.C]

Thanks for all the suggestions. Plenty of interesting boards there that I hadn't heard of.
All good food for thought.

Frank

[`FRANK.C]

I am currently using a EP4CE10 development board mounted on a  PCB that contains a TVP5150 and 2 X AL422.
I only really need one AL422.

I have managed to get the interpolater to track reasonably well. I took a video of it with the output lines varying from 96 to 540 active lines.
The video did not come out so well. The interpolater is working better than the clip would suggest. It can be view here.

Frank

[Freya]

Looking pretty good in the video

[ppppenguin]

John, those are very neat little Artix modules. Unfortunately only 7A35 on them which doesn't have enough BRAM. Need at least a 7A75.

[jjl]

Ah yes, that's true, although the Cmod A7 modules also include a 512K byte SRAM device which is of more than adequate size for a single frame store. It is a shame that they don't offer modules with the larger Artix-7 variants.

John