Pyra News: Springs are brilliant!

Discussion in 'Pyra News' started by Wally, Jun 13, 2019.

  1. Letalis Sonus

    Letalis Sonus Advanced Member

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    Eh, it's just a simple thoroughbred x86 CPU that was targeting the embedded market. It was designed to get the best performance per Watt while still being low power back then, but the result was still rather mediocre (BTW: Its bus system is based on Socket 7, the 24 years old original Pentium and K6 socket).

    The long availability is a direct result of its target audience, these kind of chips are usually used for things like industrial control systems - one does not simply replace such heavy machinery, and without a direct internet connection nobody cares that you're still using Windows XP and the like. In the end the ancient manufacturing process is even an advantage, combine it with general modern advances in lithography and you get one hell of a reliable chip - a lot of chips certified for functional safety are still being manufactured with pretty old nodes, 40+nm is still fairly common among those.
     
  2. fusion_power

    fusion_power Advanced Member

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    Yeah, and the Zilog Z80 is over 40 years old and still in glorious usage. ;) But I guess it's a different thing to "just" use these chips in embedded systems, where they only must fullfil a specific task in opposite to be the main core of an Handheld multimedia device with alot of Software and components that need to run. We need propper power saving and multimedia and HW video decoding and full 3D acceleration. Not many embedded SoC's can (or must) do that (if you don't count Raspberry Pi, Arduino & Co. ) Modern CPU stuff needs another level of support than older, well known "embedded" chips I'm sure. So OMAP & Co. may be still good for embedded stuff but it would not the best to use them for modern Handheld devices if you want to make one today.
     
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  3. levi

    levi Still fresh, damnit!

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    Yeah, but the z80 is a historical oddity. In the late 80s till mid 90s it was only popular because Zilog was the last chip maker going to publicly release their layouts, so every two-bit fab and his mate were exposing them onto wafers for the sake of it. Looking on digikey today, it does seem that Zilog is the primary manufacturer of new parts these days, presumably to fulfil the replacement parts market for old kit where the two-bob z80 has flip-flopped its last. In comparison, the chips that were almost as widely used in popular equipment at the time, the 6502 and the 68k, I found only one 68k that wasn't marked for replacement only, and no genuine 6502s at all.

    For some reason the SH-3 and SH-4 seem ubiquitous there for reasons I don't fully understand, although they might have something to do with the way hitachi seems to have exploded and populated it's IP about as far and wide as humanly possible. To be fair, Motorola's chip division did similar in the 1990s and that hasn't helped the 6509, so there must be more to it.
     
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  4. Letalis Sonus

    Letalis Sonus Advanced Member

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    The Z80 is a microcontroller rather than a fully fledged CPU, though - and microcontrollers often find a niche to stay alive. The early Game Boys' custom microcontroller was also roughly based on the 8080/Z80.

    Intel's MCS-51 (8051) reaches 40 years next year as well and there are still chips based on it in use today - I've programmed one myself in university, and some time ago I even saw a job offer at Siedle for a developer that knows this architecture (they're a leading manufacturer of intercommunication systems for buildings). You could even consider the modern Atmels to be somewhat based on the MCS-51.
     
  5. levi

    levi Still fresh, damnit!

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    Personally I've always considered the terms 'microprocessor', 'microcontroller' and 'CPU' to be basically repetition myself. Sure, they've added bits to the old chips to become the new chips as time has gone on, but that's been a piecemeal process and I can't tell you when they turned from one to the other. Perhaps there's a useful way to use those terms these days to differentiate the kind of CPUs you need for dumb washing machines and things versus those you need for fancy new TVs, but that's news to me.
     
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  6. Letalis Sonus

    Letalis Sonus Advanced Member

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    Before SoCs became common for the more juicy processors the difference was basically defined as "the chip directly includes peripherals", but nowadays you can probably roughly pin it onto having RAM and flash directly within the chip.

    It'd say pretty much everything with less than 32-bit that is still being manufactured today could be considered a microcontroller simply because the typical usage scenarios of a microcontroller are pretty much the only things these are being used for nowadays.
     
    Last edited: Jul 20, 2019
  7. Pyramancer

    Pyramancer Fairly Idle Member

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    I generally think of microcontrollers and SoCs as complete computers (with memory controller and memory on board) and microprocessors as being just one part of a computer (with an external main memory system). All have one or more CPUs.
     
  8. levi

    levi Still fresh, damnit!

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    Yeah, SoCs as a thing came about in the early 90s as I recall, and mainly referred to the DRAM controller being on board. These days, simple CPUs found in general purpose computers have USB controllers and PCI headers included. But yeah, stuff like the Z80 these days designed for new projects has onboard flash but it's not really designed for general purpose computing any more, so it should perhaps have a different name based on that property. I'd personally say that microcontrollers are of a lesser standing than microprocessors, because controlling things is a lesser thing that actually processing stuff, but I can see that might just be me.
     
  9. DrasticNerd

    DrasticNerd Long time lurker, Forum newbie

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    Thanks levi. Good to know.

    (I need the rumble for emulation. I can't think of any use - emulation-wise that is - for any of the other sensors.)
     
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