What Microchip doesn't (officially) tell you about the VSC8512 (serd.es)

I'm really enjoying this series, and this one is a good example of how working with hardware can be really difficult as manufacturers aren't always fully open (or honest) about device's capabilities. But typically you don't find that out until you're already a long way through bring-up.

This was an impressive amount of research to get what he wanted out of the device!

This is amazing.

Oh, no wonder this is so comprehensive and fearless. It's Andrew Zonenberg.

In perhaps a feat of nominative determinism, both the website and the feature are named serdes.

This has generally been my experience of PHYs in general, lots of twisty passages all different

Microchip seems to be reasonably good at opening stuff up that it's bought from other companies; various Atmel security ICs which were previously very secretive now have full datasheets freely downloadable from their site.

Token ring was old in 1996 when my masters thesis focused on error handling behavior and simulation thereof.

I wonder if there are certain elements in certain "industrial complexes" that need to maintain or interface with legacy TR systems and that's why it's still hanging around in "dark silicon".

On the topic of Microchip and secrecy: I downloaded and installed their IDE, MPLAB X IDE v6.20. It is for a pic3mx chip. The compiler looks like a completely generic gcc, built to cross-compile on a Windows host. However, they want a $1000.00 “licensing fee” in order to enable any optimization level above -O0. This seems wrong. Wouldn’t this be a violation of the copyleft license covering gcc? I’m guessing there’s some loophole, since otherwise EFF and folks would be going after them. Or perhaps they don’t know about this situation? Should I alert EFF to this situation

I adore this series and other deep dives like it.

If anyone can suggest others I would be grateful.

The thing I loathe the most about embedded work is dealing with silicon vendors and their boneheaded refusal to publish the fucking documentation and tooling.

I wish that Microchip would officially publish the programming algorithms and EE bit maps for the Atmel ATF16V8, ATF22V10 SPLDs and ATF15xx CPLDs. They programming algos have been mostly reverse-engineered (or otherwise figured out), but it'd be nice to have those published in the open, and I don't think the ATF15xx maps are completely known.

The ATF15xx have BSDL files released, but that's only for testing/bypass.

Texas Instruments has awesome documentation. Every single MSP430 microcontroller comes with:

- a family guide describing all features of microcontroller family, usually >500 pages long

- concrete microcontroller guide describing specifics of a single microcontroller, usually >50 pages long

- errata guide describing all(?) known silicon bugs with their workarounds

Also, Clang has a backend for MSP430 by default: `clang -print-targets`

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