Basic of Microcontroller (part 1)
Microcontroller (or MCU, microcontroller unit), is a computer-on-a-chip [1]. A system could be called a computer if it has at least processor, memory, and input/output (I/O) device; lack one of the three, it never be a computer. Lack of processor, it can not do any logical or arithmetic in order to process the information. Lack of memory, so where the program would take a place. Lack of I/O device, it can’t interact with "outside world", and will be useless, can’t take any advantages from it.
… [will be updated later]
