Hi, naperlou. Right you are. And the 32-bit devices have more types of communication peripherals, too--CAN, Ethernet, USB, SPI. I2C, etc., so chip creators have moved even more hardware onto silicon. That effort makes life easier for engineers and programmers.
The death of the little 8 bitters was announced several years ago, yet they still appear to be quite live with ever expanding capability. Guess they never saw their obit, much like Mark Twains quote on the exaggeration of the rumors of his death! As far as making life easier for engineers and programmers however I will disagree. The reason is with every expansion of technology comes ever more complex solutions, and with it, ever more headaches to the designer. Think autonomous cars for example, then the redundancy that must be built into them. Engineering was never easy and will not be easy in the future. In the 60s we used two transistors to make one flip flop, thus 36 bit registers took a lot of parts. Sixty-four k "core" stacks were huge and expensive, but today I whine about having "only" 16GB in my machine.
Will 32 bit machines be replaced by 64 bit? How about 128 bit guys with far more and faster registers? What are the practical limits to bus width? ASCII is still 8 bits wide.
I have been reading a lot on load sharing processor arrays lately. Sort of like multitasking in hardware. I'm not quite ready to send my 8 bit stuff to the Smithsonian quite yet. We always live in an age of discovery and I'm very happy to be alive today.
Hi, Island_Al. Yes, plenty of life left in 8-bit MCUs for a wide variety of uses. A few days ago I sketched out a neat circuit for model-railroad enthusiasts that would use an 8-bit PIC in an 8-pin package--and an assembly-language program.
Hi, AndyT. The "memory" connector is actually the connector for a TI MCU "ControlCard," already in place. The odd perspective of the image places the upper edge of the ControlCard along the same line as the far edge of the small motherboard. Look again and you'll see a board plugged in. The MCU has a lot of memory. The connector lets engineers and programmers use different types of ControlCards.
I have to disagree, 8 bits are still very much alive, especially when combined with a good compiler and plenty of memory, which is now pretty cheap. I was looking into crunching some color graphics a while ago and did two designs; one with an arm and the other with a SiLabs 8051. The 8051 was faster and cheaper in this application.
In most of the small appliances and sensors I work on, an 8 or small 16 bit machine is still my first choice. It's hard to justify a full 32 bit core when I only need 4k of code.
Long after whatever MCU that you choose has gone out of production and is not available anywhere, thye same analog ICs will still be available from multiple makers and distributors stock. So if the anticipated product life is measured in days or months, then choose the MCU approach. But if it is a product with an expected lifetime of years, then make it out of sustainable parts. (A new expression?) Cutting edge stuff often causes bleeding.
Hi, William. Yes, watch you don't get cut on the "bleeding edge" of new technologies. That said, the venerable 8051 continues to live as does the Z80 family. I believe Zilog still has variants of the Z80 family and Rabbit Semiconductor (now part of Digi International) has modules based on the Z80 architecture. Of course the x86 architecture continues to roll on, too.
Yes, it is true that the 8051 is still around, and in quite a few variants, as well. But try to find an 8047. And of course the *86 is still around. But neither of those would be considered a "small" processor, I don't think. Also, it looks a bit like many of the newer crop of small devices are constantly changing, hoping to find a configuration that is what everybody wants. The less popular versions don't lkast as long. Sort of like the flat-pack CMOS ICs of a few years back.
Of course there are also those devices that go away because of yield problems, although that may be less common than a few years back. Presently it seems that Analog Devices has stopped producing one of the audio compressor devices, and a few other audio chips, for some reason. So products do go away.
Yes, semiconductors do go away. A company called Reticon--acquired years ago by EG&G--made a programmable filter I liked very much. No replacement. Likewise, Intersil manufactured a dual-slope (integrating) amalog-to-digital converter. That went away, too, although Maxim made the chip, too, but I haven't checked recently. There are some secondary-market companies that have stocks of older ICs for companies that need replacements.
There's a balance between choosing recent semiconductors that have some history and longevity vs. picking the latest-and-greatest devices that might be a "flash in the pan." Engineers and product designers should always ask a supplier about the longevity of a device or product line.
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