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I went through a video on Youtube [2:42], that described "key difference" between a microcontroller and microprocess, apart from other differences, is that "microcontroller has a strong I/O capability so that they can derive external hardware directly, while microprocessor has weak I/O which needs transisitors to drive external hardware"

I really didnt understand why is that. Both microcontroller and microprocessor require transistors to drive external hardware. What am I missing?

This question is not pertaining to mere microcontrollers vs microprocessors, it is focused on a single distinction of "proficiency of driving external hardware"

GENIVI-LEARNER
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    I'm not going to watch the video, but that quote taken by itself sounds like nonsense to me. At the very least you need a specific definition of what "strong" and "weak" mean. – Elliot Alderson Nov 15 '19 at 18:45
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    You're not missing anything. It's an overly generalized statement with plenty of exceptions, with the easiest counterexamples being microcontrollers with low voltage and current capabilities on output pins. – Scott Seidman Nov 15 '19 at 18:52
  • The video is incorrect and misleading. The only fundamental difference now MPU's at least access to memory expansion to run something of an operating system, e.g. RTOS or Linux – Tony Stewart EE75 Nov 15 '19 at 19:10
  • @TonyStewartSunnyskyguyEE75 could you please elaborate what you mean by **MPU's at least access to memory expansion to run something of an operating system** are you talking about MMU? – GENIVI-LEARNER Nov 15 '19 at 19:13
  • @ScottSeidman The notion I got is that if you want to drive external hardware, microprocessor with OS needs to run it through the kernel using interrupts, where as in microcontroller, you could directly run the hardware or something like that. – GENIVI-LEARNER Nov 15 '19 at 19:16
  • No MPU! **Even the Moderators choice of the "Duplicate Answer" is wrong !! and will incorrectly think this I/O intensive part is an MCU** It's a low cost MPU https://i.stack.imgur.com/srbAi.png CPU's are different – Tony Stewart EE75 Nov 15 '19 at 19:16
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    That only applies if there IS an OS, there doesn't have to be. The distinctions between microcontrollers and microprocessors are getting less pronounced, with all different nifty SOCs. Generally, the microcontroller tends to have more built in peripherals. – Scott Seidman Nov 15 '19 at 19:20
  • The distinction is external access to all of extended memory address range and NOT the range of peripheral options as my link proves – Tony Stewart EE75 Nov 15 '19 at 19:22
  • @TonyStewartSunnyskyguyEE75 could you please elaborate this distinction. Do microcontrollers have external access to all of extended memory address range? – GENIVI-LEARNER Nov 15 '19 at 19:24
  • No MCU's do not need nor provide access to all of extended memory. My jpg above shows an MPU with lots of I/O but access to 32bit memory and costs only~$6 – Tony Stewart EE75 Nov 15 '19 at 19:25
  • The quote means to say EXTERNAL transistors are required, just in case you were thinking about internal transistors that are already part of the chip, just in case that was the point of confusion. – DKNguyen Nov 15 '19 at 19:53
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    I understand what the quote is trying to say but it's not a useful distinction to make. Microprocessors are optimized for performance which means there's a greater chance that the GPIO will be lower currents (<5mA) and lower voltages (<3.3V) which makes it less useful in directly driving a minority of external hardware that can be driven directly from the GPIO (like LEDs). That said, I would not inherently expect every MCU to be able to source 10-20mA from its GPIO, though I would expect the drive voltages to be 3.3V-5V. But I would not be surprised to find more powerful MCUs that don't. – DKNguyen Nov 15 '19 at 19:58
  • @DKNguyen I think you did capture the confusion quite well. I believe thats what they meant when they said external transistors to drive the hardware is required as microprocessors cant deliver "driving power" in its GPIO to drive the hardware. i believe microcontrollers such as Arduino can to some extent. If posted as an answer i shall accept it. – GENIVI-LEARNER Nov 15 '19 at 19:58
  • @GENIVI-LEARNER Yes, but there are so few loads that require moderately measurable current which can also be driven from the tiny current capability of GPIO that it's not a useful distinction to make. You need external transistors (from the humble single-transistor all the way up to a motor driver) for pretty much everything, regardless of whether it's an MCU or processor. Heck, even high frequency power transistors require a go-between for the I/O pin in the form of a gate driver. – DKNguyen Nov 15 '19 at 20:01
  • Your edit didn't help...what is "proficiency"? Speed? Current? Voltage? How would you quantify "proficiency"? Do you assume that all of the pins of a given device will have the same proficiency? – Elliot Alderson Nov 15 '19 at 20:10
  • @GENIVI-LEARNER The question is on hold right now so can't be answered unless enough people vote for it to be re-opened. I would actually just delete the question now that your confusion about the wording is cleared up since the quote itself isn't very accurate. – DKNguyen Nov 15 '19 at 20:17
  • @ElliotAlderson Yes as already clarified here by DKNguyen, proficiency is all the features you mentioned (Speed,current,voltage). Yes i did assume all the GPIO pins of a given device shall have same proficiency. Is the question well posed now? It is however by no means duplicate as also commented by TonyStewart – GENIVI-LEARNER Nov 15 '19 at 20:44
  • @DKNguyen Your answer is also wrong and has nothing to do with MCU or MPU. CMOS driver Zout depends on port requirements and Vdd Max rating for that logic family. i.e. 3.6V vs 5.5V thus Vol/Iol=Zol – Tony Stewart EE75 Nov 15 '19 at 21:17
  • @TonyStewartSunnyskyguyEE75 I agree. I'm not saying that either MPUs or MCUs preclude one or the other. You could certainly stick whatever driver you want onto an MPU or MCU if you are designing it, but that doesn't mean there aren't tendencies, even if they aren't very reliable tendencies. – DKNguyen Nov 15 '19 at 21:20
  • There is no correlation to driver current and voltage or Vol/Iol=Zol and (Vdd-Voh)/Iol for same port type between MCU & MPU only Vdd max rating – Tony Stewart EE75 Nov 15 '19 at 21:21
  • @TonyStewartSunnyskyguyEE75 I never said there was. I don't expect every 3.3V I/O to be able to sink or source 20mA. – DKNguyen Nov 15 '19 at 21:26
  • This is getting tedious on hold. Look up my example of a cheap MPU. Io max 8mA @ 0.4Vmax @ Vdd=3.3V This means RdsOn= 50 Ohms max. Can you drive an LED with 20mA? Of course. then Vol=1.0V and Pd= 20mW Any 3.3V MPU with its 8mA ports can do this. Table 47-2 – Tony Stewart EE75 Nov 15 '19 at 21:39
  • "A microprocessor is a computer processor that incorporates the functions of a **central processing unit** on a single integrated circuit (IC)..." https://en.wikipedia.org/wiki/Microprocessor - "Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), **distinguishing these core elements** of a computer **from external components** such as main memory and **I/O circuitry**." - https://en.wikipedia.org/wiki/Central_processing_unit – Bruce Abbott Nov 16 '19 at 01:42
  • I would avoid videos like that the only takeaway at best related to your question is the drive strength between that specific mcu and that specific cpu for some of the pins. but as countless other videos you can watch will show that for countless hobby applications either one of those platforms will work (or neither). Note the drive strength for either is not always good enough and requires additional external hardware (transistors if you insist plus other components) to do the job. Which includes most hobby projects where these platforms are chosen. – old_timer Nov 16 '19 at 08:20

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