CP2105 Ver la hoja de datos (PDF) - Silicon Laboratories

Número de pieza

componentes Descripción

Fabricante

CP2105

SINGLE-CHIP USB TO UART BRIDGE

Silicon Laboratories 

CP2105

5. USB Function Controller and Transceiver

The Universal Serial Bus (USB) function controller in the CP2105 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 states are supported for power management of both the CP2105 device as well as

external circuitry. The CP2105 will enter Suspend mode when Suspend signaling is detected on the bus. On

entering Suspend mode, the SUSPEND signals will be asserted if the corresponding interface is configured for

GPIO mode. SUSPEND is also asserted after a CP2105 reset until device configuration during USB Enumeration

is complete. SUSPEND is active-low by default, but can be configured using the PROM to be active high.

The CP2105 exits the 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. On exit of Suspend mode the SUSPEND signal is de-

asserted. SUSPEND is weakly pulled to VIO in a high impedance state during a CP2105 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.

6. Asynchronous Serial Data Bus (UART) Interfaces

The CP2105 contains two UART interfaces, known as the Enhanced Communications Interface (ECI) and

Standard Communications Interface (SCI)

Each UART interface consists of the TXD (transmit) and RXD (receive) data signals as well as RTS and CTS flow

control signals. Optionally, the modem control signals DSR, DTR, DCD, and RI can be enabled for each interface.

If modem control signals are not required for the application, these pins can be configured to operate with alternate

functions, such as GPIO and SUSPEND signals. The UARTs support RTS/CTS, DSR/DTR, and X-On/X-Off

handshaking. The UARTs are programmable to support a variety of data formats and baud rates. The ECI supports

several additional UART configuration options beyond those supported by the SCI. If the Virtual COM Port drivers

are used, the data format and baud rate are set during COM port configuration on the PC. If the USBXpress drivers

are used, the CP2105 is configured through the USBXpress API. The data formats and baud rates available to

each interface are listed in Table 10.

Table 10. Data Formats and Baud Rates

Interface

Data Bits1

Stop Bits

Parity Type

Baud Rate

Enhanced Communication Interface (ECI)

5, 6, 7, and 8

1, 1.52, and 2

None, Even, Odd, Mark, Space

300 bps to 2.0 Mbps3

Standard Communication Interface (SCI)

8

1

None, Even, Odd

2400, 4800, 7200, 9600, 14400, 19200, 28800,

38400, 56000, 57600, 115200, 128000,

230400, 460800, 921600

Notes:

1. Data sizes of 5 and 6 bits are not supported at baud rates above 921600 bps.

2. 1.5 stop bits only available when using 5 data bits.

3. See “6.1. ECI Baud Rate Generation” for more details on possible baud rates for the ECI interface.

12

Rev. 1.0

Share Link: