CP2110 Datasheet, PDF (16/26 Pages) Silicon Laboratories – SINGLE-CHIP HID USB TO UART BRIDGE

CP2110
6. USB Function Controller and Transceiver
The Universal Serial Bus (USB) function controller in the CP2110 is a USB 2.0-compliant, full-speed device with
integrated transceiver and on-chip matching and pullup resistors. The USB function controller manages all data
transfers between the USB and the UARTs as well as command requests generated by the USB host controller
and commands for controlling the function of the UARTs and GPIO pins.
The USB Suspend and Resume modes are supported for power management of both the CP2110 device as well
as external circuitry. The CP2110 enters Suspend mode when Suspend signaling is detected on the bus. Upon
entering Suspend mode, the Suspend signals are asserted. The Suspend signals are also asserted after a CP2110
reset until device configuration during USB Enumeration is complete. SUSPEND is logic high when the device is in
the Suspend state, and logic low when the device is in normal mode. The SUSPEND pin has the opposite logic
value of the SUSPEND pin.
The CP2110 exits Suspend mode when any of the following occur: Resume signaling is detected or generated, a
USB Reset signal is detected, or a device reset occurs. SUSPEND and SUSPEND are weakly pulled to VIO in a
high impedance state during a CP2110 reset. If this behavior is undesirable, a strong pulldown (10 k) can be used
to ensure SUSPEND remains low during reset.
The logic level and output mode (push-pull or open-drain) of various pins during USB Suspend is configurable in
the PROM. See Section 9 for more information.
16
Rev. 1.2