What you'll learn: Why security for microcontrollers is important. What security solutions are available for microcontrollers. What questions to ask when considering a security solution. Microcontrollers (MCUs) have come a long way since their early days. With 4-bit data and all assembly language instructions verbosely described in a handful of pages in the device's datasheet, the most advanced peripheral was an analog-to-digital converter (ADC), and communication had to be bit-banged over I/O pins.