Serial Port 3f8 2f8
Serial Port 3f8 2f8
A serial port is a physical interface that allows a computer to communicate with other devices using serial data transmission. Serial ports are often used for connecting modems, printers, scanners, and other peripherals to a computer. Serial ports can also be used for debugging and programming purposes, such as accessing the BIOS settings or loading an operating system.
Serial ports are identified by their I/O port addresses and interrupt request (IRQ) lines. I/O port addresses are hexadecimal numbers that specify the location of the data registers of the serial port in the computer's memory. IRQ lines are signals that notify the CPU when a device needs attention. Each serial port has a unique combination of I/O port address and IRQ line.
Serial Port 3f8 2f8
The most common I/O port addresses for serial ports are 3F8, 2F8, 3E8, and 2E8. The most common IRQ lines for serial ports are 4 and 3. The standard assignments for the first two serial ports are:
Serial Port 1: 3F8/IRQ4
Serial Port 2: 2F8/IRQ3
These assignments are also known as COM1 and COM2, respectively. The third and fourth serial ports, if present, are usually assigned to:
Serial Port 3: 3E8/IRQ4
Serial Port 4: 2E8/IRQ3
These assignments are also known as COM3 and COM4, respectively. However, these assignments are not fixed and can be changed by the user or the operating system, depending on the availability of resources and the configuration of the devices.
To access and configure the serial ports, the user can use the BIOS settings or the operating system settings. The BIOS settings are accessed by pressing a specific key (usually F2, F10, or DEL) during the boot process. The BIOS settings allow the user to enable or disable the serial ports, change their I/O port addresses and IRQ lines, and select their mode of operation. The mode of operation can be normal (for RS-232 serial interface) or ASKIR (for amplitude keyed shift interface for infrared devices).
The operating system settings are accessed by using the device manager or the control panel. The operating system settings allow the user to install or uninstall the drivers for the serial ports, change their properties and parameters, and troubleshoot any problems that may arise. The properties and parameters include the baud rate (the speed of data transmission), the data bits (the number of bits per character), the parity bit (the error detection method), the stop bits (the number of bits that indicate the end of a character), and the flow control (the method of regulating the data flow).
Serial ports are an old but still useful technology that can connect a computer to various devices. Serial ports use simple and standardized protocols that make them compatible with many devices. Serial ports can also be used for low-level communication with the computer's hardware, such as accessing the BIOS settings or loading an operating system.
Sources:
[Serial Programming/8250 UART Programming - Wikibooks]
[SuperIO Device - Beckhoff Automation]
[BIOS串口3F8跟2E8是什么 如何设置正确 - 百度知道]