Endpoint Addressing; Usb Transceiver; Table 23.1. Endpoint Addressing Scheme - Silicon Laboratories C8051T620 Manual

23.1. Endpoint Addressing

A total of eight endpoint pipes are available. The control endpoint (Endpoint0) always functions as a bi-
directional IN/OUT endpoint. The other endpoints are implemented as three pairs of IN/OUT endpoint
pipes:

Table 23.1. Endpoint Addressing Scheme

Endpoint
Endpoint0
Endpoint1
Endpoint2
Endpoint3 Endpoint3 IN
Endpoint3 OUT

23.2. USB Transceiver

The USB Transceiver is configured via the USB0XCN register shown in SFR Definition 23.1. This configu-
ration includes Transceiver enable/disable, pull-up resistor enable/disable, and device speed selection
(Full or Low Speed). When bit SPEED = 1, USB0 operates as a Full Speed USB function, and the on-chip
pull-up resistor (if enabled) appears on the D+ pin. When bit SPEED = 0, USB0 operates as a Low Speed
USB function, and the on-chip pull-up resistor (if enabled) appears on the D- pin. Bits4-0 of register
USB0XCN can be used for Transceiver testing as described in SFR Definition 23.1. The pull-up resistor is
enabled only when VBUS is present (see Section "11.1.2. VBUS Detection" on page 61 for details on
VBUS detection).
Important Note: The USB clock should be active before the Transceiver is enabled.
C8051T620/1/6/7 & C8051T320/1/2/3
Associated Pipes
Endpoint0 IN
Endpoint0 OUT
Endpoint1 IN
Endpoint1 OUT
Endpoint2 IN
Endpoint2 OUT
Rev. 1.2
USB Protocol Address
0x00
0x00
0x81
0x01
0x82
0x02
0x83
0x03
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