Which FPGA/CPLD is suitable for VGA converter?

Thread Starter

tyro01

Joined May 20, 2021
19
I'd like to make a 640*480 VGA to 8-bit RGB or LVDS converter using low pin count FPGA/CPLD. It has to be a QFP package. 8-bitRGB and LVDS need to be able to achieve both on the same chip.

The VGA input I want to build is similar to the schematic of the ML505/6/7 Vertex-5 evaluation board, but all I need is the bare minimum of functionality. I would prefer a model with fewer pins and easier availability over the long term.
Which device is recommended?
 

andrewmm

Joined Feb 25, 2011
1,497
You say LVDS or VGA out,
very different, one is analog, one is high speed serial,

What is the input ?

crude VGA to say 4 bits is possible with resistor DAC's, to get 8 bits, resisters are not sufficient.

https://hackaday.com/2014/08/06/thp-entry-cpld-video-card-with-vga-and-ntsc/

LVDS,
a lot more complex, you need to get the encoding / high speed serial working,
what's your experience in high speed serial ?

What of the many formats is the LVDS to be used for ?
for a panel, Display port , HDMI ?
 

Thread Starter

tyro01

Joined May 20, 2021
19
Before making this plan, I was planning to use LT8668EX. but the manufacturer informed me that they could not recommend this product due to image quality issues.

So I would like to develop a single function VGA conversion IC. If it is difficult to implement LVDS output, I will use the following driver to convert to LVDS if I can only achieve the conversion to 8-bit RGB.
INPUT: VGA Signal Generator
OUTPUT:NL6448BC20
LVDS DRIVER:THC63LVDM83D
 

andrewmm

Joined Feb 25, 2011
1,497
As I understand you
the input to the FPGA / CPLD your proposing is VGA RGB ,
this is a signal nominally 1v PkPk , analog.

FPGA's / CPLDs are digital

How are you proposing to convert that analog signal to a digital one ?
 

Thread Starter

tyro01

Joined May 20, 2021
19
My knowledge is old and I knew that FPGAs are digital ICs. However, I was hoping that modern FPGAs might have some analog input functions integrated into them. I give up. Thank you.
 

Thread Starter

tyro01

Joined May 20, 2021
19
Looking at the Virtex-5 LXT/SXT/FXT schematic, it looks like RGB input is possible. However, since I am not looking at the actual input waveform, I cannot determine if this is an analog RGB input.
vga_input.jpg
 

Thread Starter

tyro01

Joined May 20, 2021
19
For large ICs, the schematic symbols are divided and written separately. I mistook them for Virtex-5 symbols. This is a very embarrassing mistake.
 
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