What is microprocessor II Microprocessor

What is microprocessor 

The progress to the VLSI (Very Large Scale Integration) technology led to the development of a microprocessor. The CPU also called microprocessor is the main IC chip on computer's motherboard. A microprocessor contains all the circuits needed to perform arithmetic logic and control functions. The core activities of a computer on a single chip are possible due to the development of microprocessor. Hence, it became possible to build a complete computer with a microprocessor. A microprocessor has a limited number of instructions that it understands is called its instruction set. Each instruction involves a series of logical operations (possibly thousands) that are performed to complete each task. Most motherboards will accept more than one type of microprocessor as far as model, manufacturer, and speed is concerned, but they generally only accept one socket type. The major microprocessor manufacturers include Intel, Motorola, IBM, Advanced Micro Devices (AMD), and Cyrix. The following are the major microprocessor design technologies. 

CISC Technology: 

CISC technology (Complex Instruction Set Computing) combines the different complex instructions into one single CPU, and each instruction has the ability to perform several tasks based on mini-programs or microcode integrated into the processor. This technology would have its drawbacks. An increased number of instructions (200 to 300) meant a much more complex processor, requiring millions of transistors. Instructions were of different lengths, using 8, 16, or 32 bits for storage. This resulted in a great deal of the processor's time being spent calculating where each instruction began and ended. This is traditional microprocessor design techniques. 

Technology used in microprocessor 

RISC Technology:

This technology was designed with less complex instructions , and the mini-programs (microcode) integrated into CISC Processors, were not entirely necessary. Using several of the less complex instructions together could complete the same tasks in less time. RISC technology (Reduced Instruction Set Computing ) takes advantage of this. Using fewer instructions (128+) requires fewer transistors , which results in reduced manufacturing costs and a more stable, cooler operating CPU. Also, each instructions is of a fixed size (32 bits). This means that the processor doesn't have to use up any of its valuable time figuring out where each instruction begins and ends . Intel's microprocessors now use a hybrid of both technologies.

Differences between CISC and RISC technologies

CISC

• CISC stands for Complex Instructions Set Computer/Computing.
• CISC microprocessors are more complex.
• CISC microprocessors are expensive to produce.
• CISC microprocessors get hot because they consume more power.

RISC

• RISC stands for Reduced Instructions Set Computer/Computing.
• RISC microprocessors are less complex.
• RISC microprocessors are cheaper to produce.
• RISC microprocessors do not get hot because they consume less power.

EPIC technology:

The Explicitly Parallel Instruction Computing (EPIC) technologies are simpler and more powerful than traditional CISC and RISC processor design technologies. This technology breaks through the sequential nature of conventional processor design technology which allows the software to communicate explicitly to the processor, when operations can be done parallel. This is the latest technology which is mainly targeted to the next generation (fifth generation)  64-bit, high end server and workstations.