Shulou(Shulou.com)06/03 Report--

Today, I will talk to you about what the data sending and receiving end of the serial port is. Many people may not know much about it. In order to make you understand better, the editor has summarized the following contents for you. I hope you can get something from this article.

The sending data and receiving data of the serial port are "TXD" and "RXD".

TXD send data Transmit (tx) Data abbreviated form

RXD accepts data Receive (rx) Data abbreviated form

TXD network definition: Transmit Data: used on RS232 and UART links.

RXD network definition: Receive Data: used on RS232 and UART links.

TXD and RXD are the terms used in single-chip microcomputer.

Single chip microcomputer serial communication RXD and TXD how to dock in detail:

The first thing you need to understand is DTE and DCE. DTE refers to data terminal equipment, and the typical DTE is computer and single-chip microcomputer. DCE refers to data communication equipment, and a typical DCE is MODEM. RXD and TXD in RS232 serial port standard are from the standpoint of DTE, not DCE. Understand this point, and then talk about the following wiring method, it is easy to understand.

When the single-chip microcomputer communicates with the computer through serial port, the RXD of the single-chip microcomputer connects with the TXD of the computer, and the TXD of the single-chip microcomputer connects with the RXD of the computer.

(1) use serial port straight-through line. When designing the circuit, the RXD of the single-chip microcomputer is connected with the TXD of the circuit board DB9, and the TXD of the single-chip microcomputer is connected with the RXD of the circuit board DB9.

(2) use serial crossing lines. When designing the circuit, because the serial port line has been crossed, the RXD of the single-chip microcomputer is connected to the RXD of the circuit board DB9, and the TXD of the single-chip microcomputer is connected to the TXD of the circuit board DB9.

This can explain why direct connection method is used in some circuits and cross connection method is used in some circuits because different serial port lines are used.

When the single-chip microcomputer communicates with the serial port equipment (such as GPRS module, carrier chip, etc.), it always reconnects the RXD with the TXD, that is, the RXD of the single-chip microcomputer connects the TXD of the equipment, and the TXD of the single-chip microcomputer connects the RXD of the equipment. (except for those specially marked that its RXD is directly connected to the single-chip microcomputer RXD, such as Huawei's EM310)

After reading the above, do you have any further understanding of the data sending and receiving end of the serial port? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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