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Topic: Maximum HDMI signal resolution (Read 905 times) previous topic - next topic

rlivio


Hi
I just bought a Vidor 4000 card and I uploaded the VidorGraphics library.
I tried the example that generates a video screen with the Arduino logo. It works, but the image that it appears has a resolution of 640 x 480.


Is this the maximum resolution obtainable on the HDMI signal?

Thanks
Livio

VStrakh

There are at least two limiting factors.

1. FPGA's high-speed i/o block can't transfer faster than 640 Mbps. That effectively limits the pixel clock at 64 MHz.

2. The SDRAM clock is 100 MHz, and throughput to it is shared between multiple users.
Even if you should be able to continuously read 16-bit pixels at 100 MHz, that leaves nothing to the camera capture interface and to the soft-core cpu running in the FPGA.  So you'll have to drop the pixel clock if you want system live.

For more details see this post from Dario.

If you're not displaying the SDRAM content, like maybe you're generating pixels on the fly, making a text interface, or sprite system (you'll have to write some new hardware in Verilog/VHDL to do that), then you could go with 1080p @ 30Hz. More realistically you'd stop at 1280x720 @ 60Hz


rlivio


Thanks for the clarification VStrakh
Bye
Livio

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