EDP CABLE

The EDP has three basic architectures. The following is a brief description of the basic architecture of DisplayPort, including the DisplayPort data transfer Main Link, AUX Channel, and Link Training.

1. main channel for video and audio data transmission

The data coding protocol adopts 8B/10B coding, through which only a Differential Signal Pair is needed to transmit data and clock simultaneously. The connector consists of four pairs of differential signal lines, or four main channels, which are used to transmit image data. Depending on the amount of data displayed, one, two or four Lane channels can be used to transmit data

EDP defines three different transmission rates, each of which can choose to use 1.62 Gbit/s, 2.7 Gbit/s or 5.4 Gbit/s. Because DisplayPort uses 8b/10b encoding, which adds a bit more data to the encoding, the maximum data transfer rate that DisplayPort can actually support is:

(4-path) x (5.4 Gbit/s per path) x (8/10 Coding Overhead) = 17.28 Gbit/s

       2.The AUX channel is used to transmit settings and instructions

The DisplayPort connector also contains a separate two-way transmission auxiliary channel called Aux Channel or AUX for short, again using two differential signal lines with a single direction rate of only about 1 Mbit/s, used to transmit settings and control instructions, and more on the use of EDP later. It also includes reading Extended display identification data information (EDID) to ensure that the correct image format is transmitted (other interfaces such as LVDS, VGA, DVI and HDMI are transmitted through I2C) ; Read the contents of DisplayPort items supported by the display, such as how many main channels, transfer rates and other items, set various display configuration registers, and read the display status register.

       3. the connection process helps to enhance the reliability of the main channel

Connection is the process of establishing a connection between the DisplayPort Transmitter and the Receiver before the data is transmitted. The sending end and the receiving end communicate with each other through AUX to determine whether the connection is successful. The connection can increase the reliability of the main channel and reduce data errors, and it can compensate the difference of electric property caused by different length and kinds of cables, especially the difference of signal routing on the system board of the transmitting end and the receiving end.