Most everything is nrnd or eol or unavailable this year, so one has to try to buy a lifetime supply of over-priced chips to keep a product in production.
The RP2040 looks like the best bet for new designs right now. Digikey has over 100K in stock for $1.00 in any quantity, and they are guaranteed to be available until 2041.
Dream on :-). The one I know of was about 40 years ago, the 6809 was sourced as 6309 from Hitachi - with some additions but it was a drop-in replacement allright. Then the 6800 was cloned by a Bulgarian institute here, I have even used some. Not sure if it was a mask copy or they designed it, there were people capable of either. I also remember Philips had a 68070 part (never touched one), perhaps they did make a plain 68000 as well.
The thing with ARM for me is similar to the thing I had (have) with x86. It is a crippled architecture by concept, way too few registers for a load/store machine (ARM). And only little endian at that... But given the options on the market what can you do. Freescale still exist within NXP but nobody is second sourcing them either, and they make plenty of ARM, too. I just love it when people say they choose ARM because of the multiple sources...
Do you mean the same microprocessor made by multiple manufacturers? I don't know of any, at least in the last 20 or 30 years. Intel 8086 and Motorola MC68000 were the last ones I know of.
You may have more luck supporting more part numbers from the same manufacturer. Especially for small microcontrollers such as the Cortex-M3 or M0, there are manufacturers that have tens of PNs with the same pinout. For example if you search digikey for "STM32G0" you will find 13 different PNs with the same LQFP48 package. If you design for the smaller part, you can probably* support all the others just by recompiling.
My late father (he passed several years before Covid) used to bring up that in boot camp at Fort Benning back in '44 they'd give them like 8 vaccines in one day. Boots and raincoats only was vaccine-day uniform, who knows why but that's supposedly how it was.
Microchips in vaccines hadn't been invented yet but it was apparently somewhat common to say "They gave me the needle with the propeller on it", "Did you get the needle with the propeller on it?" "Nah man. They gave me the one with TWO propellers on it.."
I don't recall who it was, but someone who posts (posted) a lot here used the 8051 for exactly that reason. There are multiple makers with pin compatible versions. Not fast, not elegant, but it does the job of being an MCU.
This is one reason why I write not just code for the processor, but code that creates the processor as well. My processors never go EOL. I just move them from FPGA to FPGA.
It has 16KB of execute-in-place cache and interface to an outboard qspi flash chip.
The Pi Pico includes all that, and power supplies, and USB, for $4 in any quantity. Somehow the Pi foundation forces all the distributors to have the same absurd pricing at any quantity.
that's just a matter of software all the MCUs with enough memory support that
doubt it, if it wasn't for Chipmageddon there would be plenty of MCUs in that price range
and there are now several extremely cheap ARM and RISC-V MCUs from China
yeh, so you need a $0.50 flash on the side. It is 40nm, I think most other flash MCUs are 90nm it is quite small M0+ cores and it doesn't have much in peripherals, it has programmable statemachines instead
Sure; Macintosh computers used Motorola and Hitachi CPUs and even Rockwell interchangeably for a while, in the 68000 days, and the later PowerPC chips had IBM and Motorola sources... but that didn't last long.
RiscV gives hope of a future 'standard'; China's clone-it factories might be doing true second-source today, how would one know?
Independent multiple sources are less likely than coercion by a major customer, in the brand-name-conscious west.
Yes, what I meant was that similarly to "Arduino" they provide right out-the-door an API for a particular chip's features and settings so you don't have to write your own from scratch, a non-trivial amount of work.
that wouldn't be any more second source than ARM is, In both cases the core is the same but peripherals, memory, and pinout, is all over the place for different manufacturers.
one exception might be the many clones of the now old STM32F103, when dubious sellers mark them as genuine STM most people won't nice unless they start looking at details like some code running different speed because of a different memory or higher current consumption in sleep more
I don't think every inexpensive Shenzen-special ARM derivative you could in theory get your hands on in quantity comes with a nice API for you to use that exposes all the chip's particular features in a straightforward way, no.
8051, even by Analog Devices, in their ADC portfolio with ADCs/DACs on-chip. (ADUC842) I've used them in 10 GHz XFP fiber optics transceivers. <
formatting link
>
towards the bottom.
They also do ARM, now.
Their 52 MHz ARM has a chance in a current project if I can get a radiation resistant version. Just digged that out today. ECC in the FLASH is a good start.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.