Microprocessor is a single chip CPU, microcontroller contains, a CPU and much of the remaining circuitry of a
complete microcomputer system in a single chip.
Microcontroller includes RAM, ROM, serial and parallel interface, timer, interrupt schedule circuitry (in
addition to CPU) in a single chip.
RAM is smaller than that of even an ordinary
microcomputer, but enough for its
Interrupt system is an important feature, as
microcontrollers have to respond to
control oriented devices in real time. E.g., opening of microwave ovens door cause an interrupt to
stop the operation.
(Most microprocessors can
also implement powerful interrupt schemes, but
external components are usually needed.)