The CC1 and CC2 pins of USB Type-C are channel configuration pins. They perform many functions, such as cable connection and removal detection, receptacle/plug orientation detection, and current broadcast. These pins are also used for communication required by Power Delivery and Alternate Mode. The figure below shows how the CC1 and CC2 pins indicate receptacle/plug orientation. In this figure, DFP stands for Downstream Facing Port, which acts as the host or power source in data transmission. UFP stands for Upstream Facing Port, which is a device connected to the host or power consumer. The DFP pulls up the CC1 and CC2 pins through an Rp resistor, but the UFP pulls them down through Rd. If no cable is connected, the source sees a logic high at the CC1 and CC2 pins. Connecting a USB Type-C cable creates a current path from the 5V supply to ground. Since there is only one CC wire inside the USB Type-C cable, only one current path is formed. For example, in the figure, the DFP's CC1 pin is connected to the UFP's CC1 pin. Therefore, the voltage at the DFP CC1 pin is lower than 5V, but the DFP CC2 pin remains at a logic high. Thus, by monitoring the voltages on the DFP CC1 and CC2 pins, we can determine the cable connection and its orientation. In addition to cable orientation, the Rp-Rd path also serves as a way to convey the source's current capability information. For this purpose, the power consumer (UFP) monitors the voltage on the CC line. When the voltage on the CC line has its lowest value (about 0.41V), the source can provide default USB power of 500mA and 900mA for USB2.0 and USB3.0, respectively. When the CC line voltage is about 0.92V, the source can provide 1.5A of current. The highest CC line voltage is about 1.68V, corresponding to a source current capability of 3A. The VCONN pin of USB Type-C USB Type-C is designed to provide ultra-fast data transfer speeds as well as high levels of power. These features may require the use of special cables that are electronically marked by using chips internally. Additionally, some active cables utilize redriver chips to strengthen signals and compensate for losses caused by the cable, etc. In these cases, we can power the circuitry inside the cable by applying a 5V, 1W power supply to the VCONN pin. Active cables use an Ra resistor to pull down the CC2 pin. The value of Ra is different from Rd, so the DFP can still determine the cable orientation by checking the voltages on the DFP CC1 and CC2 pins. After determining the cable orientation, the channel configuration pin corresponding to the "active cable IC" will be connected to the 5V, 1W power supply to power the circuitry inside the cable. For example, in the figure below, the valid Rp-Rd path corresponds to the CC1 pin. Therefore, the CC2 pin is connected to the power supply indicated by VCONN. The SBU1 and SBU2 pins of USB Type-C & RX and TX pins The SBU1 and SBU2 pins correspond to low-speed signal paths used only in Alternate Mode. The RX and TX pins have two sets of RX differential pairs and two sets of TX differential pairs. One of these two RX pairs, along with a TX pair, can be used for the USB3.0/USB3.1 protocol. Since the connector is reversible, a multiplexer is required to correctly reroute the data on the adopted differential pairs through the cable. Note that a USB Type-C port can support the USB3.0/3.1 standard, but the minimum feature set of USB Type-C does not include USB3.0/3.1. In this case, the RX/TX pairs are not used for USB3.0/3.1 connections and can be used for other USB Type-C functions, such as Alternate Mode and USB Power Delivery protocols. These functions can even utilize all available RX/TX differential pairs.