Silicon Laboratories EFR32xG22, Руководство пользователя

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5.3 Virtual COM Port
An asynchronous serial connection to the board controller is provided for application data transfer between a host PC and the target
EFR32. This eliminates the need for an external serial port adapter.
VCOM_ENABLE
PA05 (US1_TX)
PA06 (US1_RX)
PA04 (GPIO)
VCOM_RX
VCOM_TX
Board
Controller
EFR32
USB
Host
PC
Isolation & Level Shift
PB02 (US1_CTS)
PA00 (US1_RTS)
VCOM_CTS
VCOM_RTS
ETH
or
Figure 5.3. Virtual COM Port Interface
The virtual COM port consists of a physical UART between the target device and the board controller, and a logical function in the
board controller that makes the serial port available to the host PC over USB or Ethernet. The UART interface consists of four pins and
an enable signal.
Table 5.1. Virtual COM Port Interface Pins
Signal Description
VCOM_TX Transmit data from the EFR32 to the board controller
VCOM_RX Receive data from the board controller to the EFR32
VCOM_CTS Clear to Send hardware flow control input, asserted by the board controller when it is ready to receive more data
VCOM_RTS Request to Send hardware flow control output, asserted by the EFR32 when it is ready to receive more data
VCOM_ENABLE Enables the VCOM interface, allowing data to pass through to the board controller.
The parameters of the serial port, such as baud rate or flow control, can be configured using the admin console . The default settings
depend on which radio board is used with the Wireless STK Mainboard.
Note: The VCOM port is only available when the board controller is powered, which requires the J-Link USB cable to be inserted.
UG431: EFR32xG22 2.4 GHz 6 dBm QFN32 Wireless Starter Kit User's Guide
Peripherals
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