SLVSFN7 September 2020 TPS65982DMC
PRODUCTION DATA
The USB low-speed Endpoint is a USB 2.0 low-speed (1.5 Mbps) interface used to support HID class based accesses. The TPS65982DMC supports control of endpoint EP0. This endpoint enumerates to a USB 2.0 bus to provide USB-Billboard information to a host system as defined in the USB Type-C standard. EP0 is used for advertising the Billboard Class. When a host is connected to a device that provides Alternate Modes which cannot be supported by the host, the Billboard class allows a means for the host to report back to the user without any silent failures.
Figure 8-6 shows the USB Endpoint physical layer. The physical layer consists of the analog transceiver, the Serial Interface Engine, and the Endpoint FIFOs and supports low speed operation.
The transceiver is made up of a fully differential output driver, a differential to single-ended receive buffer and two single-ended receive buffers on the D+/D– independently. The output driver drives the D+/D– of the selected output of the Port Multiplexer. The signals pass through the 2nd Stage Port Data Multiplexer to the port pins. When driving, the signal is driven through a source resistance RS_EP. RS_EP is shown as a single resistor in USB Endpoint Phy but this resistance also includes the resistance of the 2nd Stage Port Data Multiplexer defined in Port Data Multiplexer Requirements and Characteristics. RPU_EP is disconnected during transmit mode of the transceiver.
When the endpoint is in receive mode, the resistance RPU_EP is connected to the D– pin of the top or bottom port (UFP_USB_N or DBG_USB_N) depending on the operating condition. The RPU_EP resistance advertises low speed mode only.