To understand the principle of TPE-C, first of all, we need his PN, namely the definition. Type-c port has 4 pairs of TX/RX dividing lines, 2 pairs of USBD+/D-, 1 pair of SBU, 2 CC, in addition to 4 VBUS and 4 ground wires [2].

Of course, if the receiver only need DP signal, signal, don't need a USB 3.1 that DP can make use of all four of the TX/RX difference line output, so as to realize the DP output of up to four lanes, provided the total output of up to 32.4 Gbps bandwidth (each lane can output 8. IGbps), easily implement 5 kx3k60 auxiliary video, even up to 8 k * 4 k 60 frames video (4:2:0 data), the pattern is DPonly model [2]. In addition, in order to be compatible with USB2.0, TYPE-C also retains THE USBD+/ D-signal for use by USB2.0 devices, so it only needs to use type-C interface. USB2.0 and even USB 1.0 devices can also support both sides insertion. It is worth mentioning that using USBD+/ D-with the above DP Only mode can achieve DP+USB2.0 mode. DP occupies 4 pairs of TX/RX differential wires, and USB only USES D+/D- [2]. Usually, the USB2.0 differential signal will only connect one side, because the USB Type-C Plug has no B6 or B7. USB3.1 only USES 2 pairs of TX/RX difference lines as data lines, connecting TX1/RX1 in positive interpolation and TX2/RX2 in reverse interpolation. It can be seen that in any case, there will be 2 pairs of difference lines that are not used. DP alternate mode is to load DP signals onto these 2 pairs of "redundant" difference lines, thus realizing the simultaneous operation of USB3.1 +DP [2].

Usbtype-c socket end view

Usbtype-c socket end View [2]

Type-c also provides 2 CC lines and 2 SBU lines. CC line is mainly used for Power Delivery module (PD) under the communication, the CC line is used to judge the direction of the device into: first is inserted into the plug, if is inserted, the host using CC1 to equipment and communications, the use CC2, can see the CC is using a single agreement. SBU line in DP function opens, incarnate the AUX_P/AUX_N difference in DP protocol line (it can be based on the positive and negative polarity direction changes), responsible for the transmission equipment DPCD, EDID key information such as [2]