ZHCSFQ2C November 2016 – June 2018 TUSB422
PRODUCTION DATA.
The USB Type-C ecosystem operates around a small form factor connector and cable that is flippable and reversible. Due to the nature of the connector, a scheme is needed to determine the connector orientation. Additional schemes are needed to determine when a USB port is attached, determine the acting role of the USB port (Source, Sink, active cable, audio accessory, debug accessory), and communicate Type-C current capabilities. These schemes are implemented over the CC pins according to the USB Type-C Specification 1.2. The TUSB422 provides Configuration Channel (CC) logic for determining USB port attach and detach, role detection, cable orientation, and Type-C Current detection/advertisement. The TUSB422 also contains several features such as VCONN sourcing, VBUS enable, VBUS discharge enable, detection of vSafe0V, and low standby current.
The TUSB422 provides a USB Type-C Port Controller Interface (TCPCi) allowing the USB Type-C Port Manager (TCPM) residing in an external microprocessor the ability to determine when a port partner is attached or removed, cable orientation, enable or remove power to the Type-C port. The TUSB422 implements a USB PD BMC physical layer and protocol layer for communication over the Type-C port for purposes like power negotiations, alternate mode enablement (ie DisplayPort over Type-C), and data role negotiations just to mention a few. The TUSB422 takes a message provided by external processor, calculate and append a 32-bit CRC, encode, and transmit the encoded message over the CC wire in the cable. The TUSB422 also receives data from the CC wire and determined if packet is valid or not, respond with GoodCRC, and notify external processor of its arrival by asserting the interrupt (INT_N).