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VS23S040 Guide?

Posted: Thu 2021-08-05 22:57
by jockm
Is there a VS23S040 equivalent of the VS23S010D Guide? With the larger amount of memory I presume that higher resolutions might be allowed, or at least greater color depths at higher resolutions.

Sadly health issues put a stop to my previous efforts with your ICs, but I am back at it and want to see if I can make a go using the VS23S040.

Once one has a working VGA solution, it isn't hard to add a VGA to HDMI conversion layer. Otherwise one has to look at using a LVDS driver like the RA8877 and converting the LVDS signal to HDMI

The missing part of my puzzle is understanding the VS23S040 enough to know what resolutions I can push

Re: VS23S040 Guide?

Posted: Fri 2021-08-06 18:50
by wfriedrich
My understanding is, the VS23S040 is basically 4x VS23S010D. So the guide is still valid. There is 4 bit in a control register that selects which channel is active for read/write access (reg B7h Video&Registers Block Selection register). Memory is not shared between the channels, so the resolution and colour depth limitations are still the same. (XPIXELS * YPIXELS * BitsPerPixel) + Protolines + Lines start address Table <= 1Mbit (128Kbyte)
You are not the only one working on a VGA solution with this chip. ;)
A VGA resolution of 640x480 would have one channel for the sync signals and 8 values (3 bit) per pixel for each of the 3 R, G, B colour channels for a total of 512 colours.

- Wolfgang.

Re: VS23S040 Guide?

Posted: Tue 2021-08-10 12:28
by Henrik

As far as I can tell, what Wolfgang wrote was all correct. Thanks, Wolfgang!

Kind regards,
- Henrik

Re: VS23S040 Guide?

Posted: Wed 2021-08-11 22:34
by jockm

Thank you very much! I was hoping for a higher resolution like 800x600 in low color, but 720x576 64 color isn't that far off; nor is 640x480 anything to shake a stick at.