Q7Microprocessor
Question
Q.7. How Microprocessor & Microcontroller are different from computer based controller. Explain it.
Answer
A microprocessor is a general-purpose CPU-on-a-chip requiring external memory and I/O support chips, a microcontroller integrates the CPU with on-chip memory, I/O ports, timers and peripherals for dedicated embedded control tasks, whereas a computer-based controller uses a full general-purpose computer system (with an operating system) for control, offering greater flexibility and processing power at much higher cost, size and power consumption than a microcontroller-based solution.
A microprocessor (such as the Intel 8085 or 8086) is essentially a general-purpose central processing unit (CPU) fabricated on a single chip, containing the ALU, control unit and register set, but requiring external chips for program/data memory (ROM/RAM) and input/output interfacing (such as the 8255 PPI) to form a complete, functional computing system — this makes a microprocessor-based system flexible and suited to general-purpose computing applications (personal computers, workstations) where memory and I/O requirements vary widely and are best implemented with separate, appropriately-sized external components.
A microcontroller (such as the 8051) integrates the CPU core together with on-chip program memory (ROM/Flash), on-chip data memory (RAM), I/O ports, timers/counters, and often a serial communication interface, all on a single chip — this makes a microcontroller a complete, self-contained embedded computing system requiring minimal or no external components for many applications, at the cost of generally more limited memory capacity, processing power and peripheral flexibility compared to a full microprocessor-based system with its separately-selected external memory/I/O components. Microcontrollers are specifically designed and optimized for dedicated, embedded control applications (appliance control, automotive control modules, simple robotics, sensor/actuator interfacing) where a fixed, well-defined, relatively modest set of processing and I/O requirements can be met economically by a single, low-cost, low-power integrated chip.
A computer-based controller uses a complete general-purpose computer system (a PC, single-board computer, or industrial PC) running a full operating system (Windows, Linux, or a real-time OS) to perform control tasks, offering vastly greater processing power, memory capacity, software development flexibility (high-level programming languages, extensive libraries, networking stacks, graphical user interfaces) and ease of integrating complex algorithms or user interfaces than either a microprocessor or microcontroller-based embedded solution, but at substantially higher cost, physical size, power consumption, and typically longer/less deterministic response times (unless a specifically real-time operating system and hardware configuration is used) compared to a dedicated microcontroller solution. Computer-based controllers are used where the control application genuinely demands the computational power, software flexibility, storage capacity, networking, or user-interface sophistication that only a full computer system can practically provide — such as complex industrial SCADA/supervisory control systems, machine-vision-based inspection systems, or applications requiring extensive data logging, complex algorithms, or rich graphical operator interfaces — whereas the vast majority of simpler, well-defined, cost- and power-sensitive embedded control tasks (which represent the overwhelming majority of all embedded applications by volume) are more economically and efficiently served by a dedicated microcontroller.