How do CPU transfer data from input to output?

Answer 1

The process of transferring data from input to output in a CPU (Central Processing Unit) involves several steps and components working together. Here's a simplified explanation of how this process typically occurs:

1. Input Devices: Data is first entered into the computer system through various input devices such as keyboards, mice, touchscreens, scanners, or network connections. These input devices convert physical actions or signals into digital data that the computer can process.

2. Input/Output Controller (IO Controller): Input data from devices may pass through an Input/Output Controller, which manages the communication between the CPU and the input/output devices. The IO Controller may handle tasks such as buffering data, converting signals, and coordinating data transfer between devices and memory.

3. Data Bus: The CPU communicates with other components of the computer system, including input/output devices, through a data bus. The data bus is a set of wires or pathways that allow data to be transferred between different components of the computer system.

4. Memory: Data may be temporarily stored in the computer's memory (RAM) before being processed by the CPU. This allows the CPU to quickly access the data it needs for processing.

5. CPU Processing: The CPU retrieves data from memory and performs various processing tasks on it, such as calculations, data manipulation, or executing instructions. The CPU contains registers, caches, and arithmetic logic units (ALUs) that facilitate these processing tasks.

6. Output Devices: Once processing is complete, the CPU sends the resulting data to output devices such as monitors, printers, speakers, or network interfaces. Output devices convert digital data into physical forms that are usable or understandable to humans.

7. Output Controller: Similar to the input/output controller, an output controller may manage the communication between the CPU and output devices, handling tasks such as data buffering, signal conversion, and coordination of data transfer.

8. Data Bus (again): The processed data is transferred from the CPU to the output devices via the data bus, allowing for communication between these components.

Throughout this process, the CPU coordinates the transfer of data between input, memory, processing, and output components, ensuring that data is processed accurately and efficiently. The specific mechanisms and protocols used for data transfer may vary depending on the computer architecture and the types of input/output devices involved.

Answer 2

While the computer is running, the CPU runs atomic instructions which are read from harddisk into memory (RAM), and which each manipulate a small piece of data. In accumulation these instructions lead to the result of the apparent connection of input (for example, typing the keyboard) to output (for example, displaying stuff on screen). The atomic instructions used are somewhat different for each CPU, but common desktop PCs use extensions of the x86 instruction set.

see: http://en.wikipedia.org/wiki/X86_instruction_set