Microcontrollers & Memory

Microcontrollers & Memory

Use this page to revise what an MCU is and how its memory and I/O are organised.

MCU vs. microprocessor

A microcontroller typically integrates CPU, flash, RAM, and peripherals on one chip. A microprocessor needs external chips for memory and I/O (a Pi-class SoC sits in between). Studio boards (ESP32, STM32, AVR) are MCU-class devices.

Memory

• Flash: program and often constants.
• SRAM: stack, heap, globals; scarce.
• Memory map: regions and peripheral registers.
• DMA moves data without the CPU in the loop (ADC buffers, SPI).

GPIO and clocks

GPIO pins have modes (input, output, alternate function). Clocks and PLL settings determine how fast the core and peripherals run — wrong clock, wrong baud rate.

Starting Points

• Computer systems & architecture
• Microcontroller programming & flashing
• Vendor block-diagram page for your board's MCU.

Key Points

• You can contrast a microcontroller with a microprocessor.
• You can explain flash vs. SRAM and why SRAM size limits firmware design.
• You can explain what a peripheral register and a memory map are for.
• You can explain GPIO modes and why clock configuration affects UART baud and timers.
• You can explain DMA in one sentence and when you would want it.