Bit-banging video with an STM32F4 ARM SoC, an SoC which doesn't natively do video. A multipart blog series by Cliff L Biffle.
Producing video with one chip and a few resistors: the trick being that the chip lacks video support. Some interesting questions raised and addressed: latency, jitter, interrupts, cache effects, limitations of the chip's interconnect.
http://cliffle.com/project/glitch-demo/The end result - some tight code indeed - is packaged up an as open source library. Cliff writes:
Quote:
I’m working on a series of posts on the internals. Here’s what we’ve got so far:
Introduction — with a brief explanation of why I think this is interesting.
Pushing Pixels — a look at the options for jitter-free parallel output on STM32F4, and why I chose the one I did.
A Glitch in the Matrix — sources of jitter in the STM32F407 and how to fix them, with a focus on the AHB bus matrix.
Racing the Beam — making pixels as they’re needed with rasterizers.
