A CDP is a USB port that follows USB BC1.2 and supplies a minimum of 1.5A per port. It provides power and meets USB 2.0 requirements for device enumeration. USB 2.0 communications is supported and the host controller must be active to allow charging. What separates a CDP from an SDP is the host-charge handshaking logic that identifies this port as a CDP. A CDP is identifiable by a compliant BC1.2 client device and allows for additional current draw by the client device.The CDP hand-shaking process is done in two steps. During step one the portable equipment outputs a nominal 0.6V output on its D+ line and reads the voltage input on its D- line. The portable device concludes it is connected to an SDP if the voltage is less than the nominal data detect voltage of 0.3V. The portable device concludes that it is connected to a Charging Port if the Dvoltage is greater than the nominal data detect voltage of 0.3V and optionally less than 0.8V.The second step is necessary for portable equipment to determine if it is connected to CDP or DCP. The portable device outputs a nominal 0.6V output on its D- line and reads the voltage input on its D+ line. The portable device concludes it is connected to a CDP if the data line being read remains less than the nominal data detection voltage of 0.3V. The portable device concludes it is connected to a DCP if the data line being read is greater than the nominal data detect voltage of 0.3V.PI5USB2546A series supports CDP mode in system power state S0 when system is completely powered ON and fully operational. For more details on control pin (CTL1, CTL2, CTL3 and ILIM_SEL) settings to program this state please refer to device truth table.