5 ms·
Editorialized title; its not part of the MCU family, its part of the MPU family
by zokier 3y ago
Editorialized title; its not part of the MCU family, its part of the MPU family
- topspin 3y agoIndeed, this is an embedded SOC, not an MCU. Very nice device.
- unwind 3y agoYes, my bad, thanks. Don't think I can change it now, though.
- gaudat 3y agoAnd the line between the two is blurred now with MCU running at hundreds of MHz. The STM32H7 is has more IPC than the original Raspberry Pi.
- dragontamer 3y agoDo you take external DDR RAM on an application-class ARM core? You're an MPU. There's a blurry line sometimes, but Application-class (Cortex A* cores, like A5, A35, etc. etc.) are solidly MPU. Not even close.
- eqvinox 3y ago> Do you take external DDR RAM on an application-class ARM core? You're an MPU. The actual difference IMHO is the existence of an MMU. (Which is, fdpic/linux-nommu efforts notwithstanding, the general "Linux" condition.) (Ex.: the SOPHGO SG2000 RISC-V chip comes with integrated DDR3 RAM, but is still solidly an MPU. I believe there are some ARM Cortex-A with integrated RAM too, can't think of any off the top of my head. [Ed.: nevermind, the SG2000 is dual RISC-V/ARM])
- bpye 3y agoNuvoton have some ARM9 parts with integrated DRAM for example [0]. It’s a little outdated but this blog post is a pretty good overview of the options available [1]. [0] - https://www.nuvoton.com/products/microprocessors/arm9-mpus/ https://www.nuvoton.com/products/microprocessors/arm9-mpus/ [1] - https://jaycarlson.net/embedded-linux/ https://jaycarlson.net/embedded-linux/
- vbezhenar 3y agoIf it runs Linux, it's MPU. If it runs bare firmware, it's MCU.
- stratom 3y agoNo this not a really good criteria. There is Linux support for a few MCUs, including a few STM32 Series. Having a MMU is a much better criteria.
- SAI_Peregrinus 3y agoThen the 8-bit ATMega328p in the Arduino Uno is an MPU[1]. Except it's solidly an MCU. I'd say if it uses external RAM as its main memory, and external storage as its main storage, then it's an MPU. If the RAM is all internal, and the storage is all (or can be all) internal, it's an MCU. [1] https://github.com/raspiduino/arv32-opt https://github.com/raspiduino/arv32-opt
- vbezhenar 3y agoThat’s a gimmick. I’m talking about how given chip is supposed to be used in a real products, whether vendor supplies Linux builds in one way or another, etc.
- sam_bristow 3y agoIt's even more blurred with this vhip because it sound like it has both a 64-bit Cortex-A35 MPU and a 32-bit Cortex-M33 MCU core. As an aside, I'm pretty sure these chips were announced months ago despite what the article says.
- demondemidi 3y agoWhat’s the diff between an SoC and MPU? Lack of a wireless connectivity subsystem?
- dragontamer 3y agoWell, SoC is different again. We're talking MCU, microcontrollers. For ARM, its rather simple. Cortex-M cores are MCUs, while Cortex-A cores are Microprocessors. Cortex A72?? That's a Microprocessor. Cortex M7? This is a Microcontroller.
- dljsjr 3y agoMPU -> Microprocessor. MPUs typically have features that let it support a "full" OS; MMUs, speculative execution, advanced CPU pipelining features, etc. They also have a much higher RAM capacity. Often has more complicated power requirements when doing board design due to needing different voltage busses for different peripherals. Usually can't be run standalone, you have to bring some of your own peripheral hardware. For example, you usually need to bring your own RAM. MCU -> Microcontroller. Low power, less RAM, limited MMU/memory protection features, typically run baremetal firmware or an RTOS. Usually so simple it only needs a single voltage rail. More or less self-contained. Has RAM and ROM on-die. SoC -> System-on-a-chip. Actually a very vague term. But in broad strokes, an SoC is what it says: An entire system on a single chip. Could incorporate an MCU or an MPU, plus other peripherals, etc. You can almost think of it as a "single chip computer" as opposed to a "single board computer". It's almost more of a marketing term than an EE term. For example, the Apple Silicon stuff is a "SoC" because it has the MPU + GPU + RAM on a single die.
- m-ee 3y agoI tend to think of an SoC as "MCU with other peripherals not typically on an MCU", so BLE/WiFi radio or maybe gate drivers for motor control. But usually radios. As you pointed out "not typically on an MCU" is a moving target. Was a point where RAM and a decent ADC would be things you had to add externally.
- demondemidi 3y agoThe definition of MPU is basically CPU, no?