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Microprocessors and -controllers

Microcontroller
  • microcontroller vs -processor

    • MCU

    An MCU is a group of microcontroller units that share a common architecture, design, and often the same core features

    • ARM Cortex-M is a popular MCU family, where multiple manufacturers like STMicroelectronics, NXP, and Microchip produce MCUs that are based on the ARM Cortex-M core.
    • AVR is another MCU family, famously used in the Arduino platform.
    • PIC is a family of MCUs from Microchip Technology, with a range of devices from small 8-bit controllers to more powerful 16-bit and 32-bit versions.

    Within each MCU family, you’ll typically see models that differ by features like:

    • Flash memory size
    • RAM size
    • Clock speed
    • Number of GPIO pins
    • Peripheral support (e.g., UART, SPI, I2C, timers, etc.)

    In-System Programming (ISP)

    • the act of programming a microcontroller while it is already mounted on the board
    • Contrary to Pre-Programming. You program the contro

    CMSIS-DAP Devices are all devices that can write programs into a microcontroller's memory using JTAG or SWD. ler before soldering it somewhere.

    Available Controllers

    At least 5 of each:

    • SEEEDSTUDIO XIAO SAMD21 NO HDRS
    • SEEEDSTUDIO XIAO ESP32C3 NO HDRS
    • SEEEDSTUDIO XIAO ESP32S3 NO HDRS
    • SEEED STUDIO XIAO RP2040 ARDUINO
    • ATSAMD11C14A-SSUT
    • ATSAMD21E18A-AUT
    • ATTINY412-SSFR
    • ATTINY1624-SSFR
    • ATTINY3226-SU
    • AVR128DB32-I/PT

    QFP mit Beinchen seitlich
    TQFP ohne Beinchen
    Soic-8 8 Beinchen
    Punkt oder Kerbe kennzeichnen Pin 1

    Putting code onto it

    In-System Programming (ISP)

    • the act of programming a microcontroller while it is already mounted on the board
    • Contrary to Pre-Programming. You program the contro

    CMSIS-DAP Devices are all devices that can write programs into a microcontroller's memory using JTAG or SWD. ler before soldering it somewhere.

    Serial Peripheral Interface (SPI)

    • A standard synchronous serial communication interface used for short-distance communication between a main device and one or more peripheral devices.
    • synchronous (needs clock signal), serial communication
    • multiple secondary devices are possible
    • full-duplex
    • pins:
      • MOSI (main out secondary in)
      • MISO (main in secondary out)
      • SCK (clock)
      • SS (secondary select): select which secondary device to communicate with

    Serial Peripheral Data Interface (SPDI)

    • do not find any source for it

    Joint Test Action Group (JTAG)

    • eletronics manufacturers committee
    • they developed a protocol with the same name
    • mostly used for programming ARM cores
    • pins
      • TMS: mode select
      • TCLK: clock
      • TDO: data out
      • TDI: data in
      • nRESET: reset (optional)

    Serial Wire Debug (SWD)

    • two-pin variant of the JTAG protocol
    • most common on newer ARM chips
    • pins:
      • swdio: in/out
      • swclk: clock

    Unified Program and Debug Interface (UPDI)

    • proprietary
    • single-wire,
    • bi-directional, half-duplex
    • asynchronous
    • can use off-the shelf UART adapters
    • used to program AVR microcontrollers released since 2016, ATTINY412, ATTINY164.
    • more detailed blog article
    • debugging is hidden behind a proprietary interface, but even though you can snoop on the protocol with just a serial adapter and even though the large scale structure of the protocol is known too
    • even more detailed article
    • i did not find out what part of the protocol actually is proprietary and what not.

    Difference between microcontroller and -processor

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