微处理器与微控制器的区别

COMPARING MICROPROCESSORS AND MICROCONTROLLERS
• 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 applications.
–Interrupt system is an important feature, as microcontrollers have to respond
to control oriented devices in real time. E.g., opening of microwave oven’s
door cause an interrupt to stop the operation. (Most microprocessors can also
implement powerful interrupt schemes, but external components are usually
needed).
• Microprocessors are most commonly used as the CPU in microcomputer systems.
Microcontrollers are used in small, minimum component designs performing
control-oriented activities.
• Microprocessor instruction sets are processing intensive, implying powerful
addressing modes with instructions catering to large volumes of data. Their
instructions operate on nibbles, bytes, etc. Microcontrollers have instruction
sets catering to the control of inputs and outputs. Their instructions operate
also on a single bit. E.g., a motor may be turned ON and OFF by a 1-bit
output port.