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

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Re: What Microchip doesn't (officially) tell you about the VSC8512

#41

Post by mardifoufs »

jmiskovic wrote: post #37
stephen_g wrote: post #19

Earlier quoted context omitted.

Yeah I’m really not a fan - we had some designs with PICs on them and ended up switching to NXP micros (MCX-A and i.MX-RT) instead, partly because of MPLAB and also because the Microchip ones had some annoying quirks. NXP’s documentation I find a lot better too. I literally try to avoid Microchip where I can from the experience…

Personally I hated the NXP's docs for the ARM M4 core. Bunch of dry tables listing each register in details, lacking the juicy diagrams and descriptions on how the bits integrate to work as a subsystem. I constantly needed to cross-reference 3+ documents (most of which describe the whole family and not the specific IC). Their HALs and code samples were obviously written by students/interns. I liked working with Micro…

Yeah, NXP in my experience had an issue with having too much documentation. In the sense that you get drowned in a 3000 pages PDF that lists every detail but becomes hard to parse unless you want to base everything around that specific platform for years. Though that sounds like an awesome "issue" to have in some circumstances.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#42

Post by stephen_g »

ACCount36 wrote: post #39
traverseda wrote: post #35

Earlier quoted context omitted.

Why though? This is clearly a problem I just don't understand what the vendors are getting out of it.

Perhaps they think that by forcing everyone to go through the sales dept just to get the basic docs, they'll get better sales opportunities. How do you upsell a hardware engineer who just wants to buy a specific chip, and already has everything to evaluate and use it? You don't. So you force everyone to go through sales, and then sales wants to talk to non-engineering higher-ups, and then the upsell happens - while t…

They don’t care about ‘upselling’ - it’s just that they only really care about the orders that are at least in the tens of thousands of units (or for the Broadcoms of the world, hundreds of thousands) per year, and ongoing.

If you even promise to buy a few hundred a year through a business, it puts you in a different category and everything gets much easier, but you usually have to go via a distributor (Avnet, Future, Arrow etc.). But if you’re big enough (the hundreds of thousands + qtys) these companies will actually send dedicated support engineers to work with you and help you integrate their parts into your product.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#43

Post by stephen_g »

junon wrote: post #25
ACCount36 wrote: post #24

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.

Microchip in particular is very bad at developer experience and tooling. The only vendor I actually enjoy working with to any degree is ST, and only design boards using their uC's for that reason. I've heard good things about Nordic, though. Might try them out at some point. Microchip's own IDE and project generator spit out a hello world project that didn't even compile. NXP wouldn't even let me download their tooli…

Which NXP tooling did you have trouble with? I’ve downloaded MCUXpresso earlier this week, no NDA or anything (yes you do need an account), it’s never been hard to get…

Re: What Microchip doesn't (officially) tell you about the VSC8512

#44

Post by stephen_g »

Taniwha wrote: post #7

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

It doesn’t help that this is a Vitesse Semiconductor part that became a MicroSemi part that became a Microchip part through a bunch of mergers and acquisitions…

Re: What Microchip doesn't (officially) tell you about the VSC8512

#45

Post by Tuna-Fish »

rkangel wrote: post #38
lmz wrote: post #31

Earlier quoted context omitted.

Of course that depends if the optimization was compiled into the version they have. One can imagine two binaries with the optimizations just missing from the free one.

If they distribute the one with optimisations, then they need to make the source available.

... but only to the ones they distribute it to. They can then choose to redistribute it if they want to.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#46

Post by thyristan »

rbanffy wrote: post #20
MrBuddyCasino wrote: post #18

Earlier quoted context omitted.

AFAIK Ethernet is used for realtime audio distribution, so that can't be completely correct.

There is audio distribution real-time and nuclear reactor (or avionics, medical, etc) real-time. I assume the people doing (or certifying) the latter will want better guarantees.

The usual terminology is hard, firm and soft realtime. In hard realtime, missing a deadline is a total failure and to be avoided at all cost, i.e. your reactor melts down, you car runs over someone, stuff like that. Firm realtime means that a missed deadline will not be a total catastrophic failure but it will make the result useless. E.g. when your printer control system mistimes the "fire ink now" in the printer, and the ink lands not on the page but somewhere else. Soft realtime means that your result will gradually degrade with missed deadlines, but not be totally useless.

Audio is usually soft realtime, sometimes, e.g. when doing studio recordings, firm realtime.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#47

Post by Sanzig »

Gracana wrote: post #34
junon wrote: post #25

Earlier quoted context omitted.

Microchip in particular is very bad at developer experience and tooling. The only vendor I actually enjoy working with to any degree is ST, and only design boards using their uC's for that reason. I've heard good things about Nordic, though. Might try them out at some point. Microchip's own IDE and project generator spit out a hello world project that didn't even compile. NXP wouldn't even let me download their tooli…

I was on the Microchip bandwagon until the PIC32. Little MIPS MCUs with onboard RAM and graphics, awesome! ...except they came with an errata that listed huge problems with every interesting peripheral, and it didn't improve for ages. They may still suck, I don't know. A while back I tried out Espressif's esp32 and I was impressed by what they were offering. Their devices seem to be well documented and the esp-idf fr…

I really like the STM32 ecosystem, but you have hit the nail on the head - there's too many variants. You really don't need 200 variations of a basic M0+ part, and having all those SKUs hurts availability because you're playing roulette when it comes to what will actually be in stock when your CM goes to order parts.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#48

Post by azonenberg »

znpy wrote: post #23
fragmede wrote: post #13

Earlier quoted context omitted.

The GPL doesn't say you can't charge money for things. Do they provide patches for their changes to the source?

I think that the issue here is the following: - you can charge money for things - anything that's not built with the "official compiler" is not "supported" I've interviewed for a junior embedded software engineer when i was in university and when i started mentioning i had experience building cross-compilers i was immediately stopped by the guy interviewing me (he literally didn't even let me finish the sentence) and…

I have not used anything but arm-none-eabi-gcc for STM32s from day one. Never even installed CubeMX or any other ST software.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#49

Post by azonenberg »

userbinator wrote: post #8

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.

Yes, Vitesse had been on my "naughty list" of companies that were permanently banned from getting a design win from me because of refusing to share any docs or sell parts at distributors or other engineer-hostile practices popular with the likes of Marvell and Broadcom.

After MCHP bought them and opened up (what I thought was) the full datasheet I gave them a second chance. Seems they still held some back.

Re: What Microchip doesn't (officially) tell you about the VSC8512

#50

Post by azonenberg »

ACCount36 wrote: post #26
junon wrote: post #25

Earlier quoted context omitted.

Microchip in particular is very bad at developer experience and tooling. The only vendor I actually enjoy working with to any degree is ST, and only design boards using their uC's for that reason. I've heard good things about Nordic, though. Might try them out at some point. Microchip's own IDE and project generator spit out a hello world project that didn't even compile. NXP wouldn't even let me download their tooli…

True, and Microchip is still good when compared to the likes of Broadcom and Qualcomm.

This is why I used a VSC PHY. After they bought Microsemi (and Vitesse as a division of Microsemi) it looked like the only viable option to get a QSGMII PHY since all the other players were much worse.

When I first started the project in 2012-13, Vitesse was just as NDA-happy and I ruled them out. The original roadmap called for a 24-port switch with 24 individual TI DP83867 SGMII PHYs on three 8-port line cards.

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