Virtual Com Port - Silicon Laboratories SLSTK3701A User Manual

6.12 Virtual COM Port

An asynchronous serial connection to the board controller is provided for application data transfer between a host PC and the target
EFM32. This eliminates the need for an external serial port adapter.
PH4 (US4_TX #4)
PH5 (US4_RX #4)
PH8 (US4_CTS #4)
PH9 (US4_RTS #4)
PE1 (GPIO)
EFM32
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. The UART interface consists of four pins and an enable
signal.
Signal Description
VCOM_TX Transmit data from the EFM32 to the board controller
VCOM_RX Receive data from the board controller to the EFM32
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 EFM32 when it is ready to receive more data
VCOM_ENABLE Enables the VCOM interface, allowing data to pass through to the board controller.
Note: The VCOM port is only available when the board controller is powered, which requires the J-Link USB cable to be inserted.
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Isolation & Level Shift
VCOM_TX
VCOM_RX
VCOM_CTS
VCOM_RTS
VCOM_ENABLE
Figure 6.12. Virtual COM Port Interface
Table 6.1. Virtual COM Port Interface Pins
UG287: EFM32 Giant Gecko GG11 Starter Kit User's Guide
USB
Board
Controller
Peripherals
Host
PC
Rev. 1.10 | 23