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This article will explain in detail about the functions of the controller in the computer. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

The function of the controller is to direct and coordinate the work of various parts of the computer. The controller consists of a program counter, an instruction register, an instruction decoder, a timing generator and an operation controller.

This article operating environment: windows10 system, thinkpad T480 computer.

The function of the controller is to direct and coordinate the work of various parts of the computer.

What is a controller?

The controller refers to the main command device which controls the starting, speed regulation, braking and reverse of the motor by changing the wiring of the main circuit or control circuit and changing the resistance value in the circuit according to the predetermined order. It is composed of program counter, instruction register, instruction decoder, timing generator and operation controller. it is the "decision-making body" that issues commands, that is, to coordinate and direct the operation of the whole computer system.

Basic functions:

Data buffering: a buffer must be set in the controller because the speed of the Istroke O device is low while the rate of CPU and memory is very high. On output, the buffer is used to temporarily store the data transmitted at a high speed from the host, and then the data in the buffer is transmitted to the Icano device at the rate that the Icano device has; on input, the buffer is used to temporarily store the data sent from the Icano device, and after receiving a batch of data, the data in the buffer is transmitted to the host at a high speed.

Error control: the device controller is also responsible for error detection of data transmitted by the Istroke O device. If an error is found in the transmission, the error detection code is usually set and reported to CPU, so CPU invalidates the data transmitted this time and transmits it again. This ensures the correctness of the data input.

Data exchange: this refers to the data exchange between CPU and controller, and between controller and device. For the former, the data is written to or read out from the controller in parallel by the CPU through the data bus; for the latter, the device inputs the data to the controller or transmits it from the controller to the device. For this reason, a data register must be set in the controller.

Status description: the status controller that identifies and reports the device should write down the status of the device for CPU to know. For example, CPU can start the controller to read data from the device only if the device is in a send-ready state. For this reason, a status register should be set in the controller, and each bit in it should be used to reflect a certain state of the device. When CPU reads the contents of the register, you can understand the status of the device.

Receive and identify commands: CPU can send a variety of different commands to the controller, and the device controller should be able to receive and recognize these commands. For this reason, there should be corresponding control registers in the controller to store the received commands and parameters, and to decode the received commands. For example, the disk controller can receive 15 different commands from CPU, such as Read, Write, Format, etc., and some commands have parameters; accordingly, there are multiple registers and command decoders in the disk controller.

Address recognition: just as every unit in memory has an address, every device in the system has an address, and the device controller must be able to identify the address of each device it controls. In addition, in order for CPU to write (or read) data to (or from) registers, these registers should have unique addresses.

This is the end of this article on "what are the functions of the controller in the computer". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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