What are microprocessors? Types of microprocessors

Computer technology allows us to work with considerable efficiency. But how do they function at all? This helps a range of different devices and devices. And one of them is a microprocessor. What it is? What are its functions? What are the characteristics of this device? What is microprocessor architecture? What parameters depend on it?

What are microprocessors?

This is the name of a device that is programmatically controlled. Its task is to process and manage digital information. The microprocessor control must be small, but at the same time functional. From this emerges a number of properties, which will now be told. The microprocessor is implemented on (super) large integrated circuits ((C) LSI), which can be several pieces. For them, the following are characteristic:

1. Low cost (refers to mass production).
2. Simplicity of manufacture (on one technology);
3. It occupies little space (several square centimeters or even millimeters).
4. High reliability.
5. Consume little energy.

The device of the microprocessor significantly depends on the construction of its architecture. Further on this will be discussed and within the framework of the article three types will be considered.

Functions

This is what makes them generally created. So, the functions of the microprocessor are:

1. Read and decode commands that come from the main memory.
2. Accept and process requests from adapters for the maintenance of external devices (VU).
3. Read data from RAM and VU registers.
4. Create control signals that control other nodes and blocks of a personal computer.
5. They process the data and record it in the RAM, as well as registers of external devices.

Main characteristics of the microprocessor

In total, there are four:

1. Bit depth.
2. Performance.
3. Command system.
4. The amount of addressable memory.

Groups of microprocessors

They are distinguished by three:

1. CISC. There is a full set of commands.
2. RISC. There is a shortened set of commands.
3. MISC. There is a minimum set of commands, but they have very high speed for both this class of devices.

CISC type microprocessors

They can work as part of a computer network. There is also the possibility of multitasking and memory protection. Microprocessors of this type can function in two modes: protected and real. The first provides the possibility of multitasking and immediate access to extended memory. In addition, it is protected from extraneous messages. In real mode, the 8086 microprocessor is emulated and there is a single-task operation.

Microprocessors of type RISC

They have simple most used commands. If you need to perform something complicated, you "build" the required functionality. To execute a command, only one machine clock is wasted due to parallel execution and overlapping. For comparison, in CISC the smallest will go as many as four.

What does the microprocessor consist of?

It is divided into two parts:

1. Operating room. Contains control devices, arithmetic logic and microprocessor memory.
2. Interface. It contains address registers, port and bus management schemes, and a block of commands.

Important is architecture - the logical organization of the microprocessor, which determines its features, properties and the ability to build a computer system based on this device. There are three main types: CISC, RISC and MISC (this is, speaking of universal devices). So, in them there are several groups of registers that work with different degrees of anticipation. This allows you to perform operations literally "in pipeline mode." This positively affects the effective speed. The microprocessor of the computer usually serves only one device - say, a keyboard.

CISC Architecture

Complex Instruction Set Computer - comprehensive instructions for the computer. The characteristics of a microprocessor with this architecture are as follows:

1. Have a large number of teams that differ in their functionality, length and format.
2. Different addressing systems are used.
3. There is a complex encoding of commands.

What are the microprocessors of this architecture? These are complex devices, the main focus of which is on functionality.

RISC Architecture

Reduced Instrucktion Set Computer - homogeneous instructions for the computer. The characteristics of a microprocessor with this architecture are as follows:

1. Applies a simplified type of command system: they all have the same format with a simple coding. Data from RAM to the microprocessor register and vice versa are moved using boot instructions.
2. Despite the high speed, these microprocessors can have a relatively low clock speed and a lesser degree of integration of VLSI.
3. Teams perform less load on RAM.
4. But to debug the work of programs on RISC is much more complicated than on CISC.
5. It is not possible to use the same programs with CISC.

MISC Architecture

Multipurpose Instruction Set Computer - multi-purpose instructions for computer management. It is an attempt to combine the advantages of CISC and RISC. Here the element base is assembled from separate parts (which are often combined in one body):

1. Main part. It is based on the RISC architecture.
2. Expandable part. On it is a connected ROM firmware.

The system itself acquires the properties of CISC. So, the main teams here work on a basis provided by RISC. At the same time, there is an extension that "creates" the firmware. The RISC base performs all of its commands in one step. And the extension uses a complex set of commands. Due to the presence of ROM, the disadvantage of RISC is eliminated, that when the operation code is compiled from a high-level language, it is already decrypted and open for the programmer. That's what microprocessors are, and they should have such properties from the point of view of the given architecture of their construction.

Conclusion

What are microprocessors and what is the basis of their functioning - we have considered this. Of course, to understand all the nuances of these devices, it is necessary to devote a lot of time and get acquainted not with one book and a collection of lectures. But the basis itself is already there.