The interface MCU has two virtual serial ports, each with a Universal Asynchronous Receiver/Transmitter (UART) interface.
The serial ports have the following features:
- Flexible baud rate setting up to 1 Mbps (baud rate 921 600 bps is not supported)
- Dynamic Hardware Flow Control (HWFC)
- Tri-stated UART lines when no terminal is connected
The following table describes the signals between the interface MCU and the nRF5340 System on Chip (SoC) and the associated UART GPIO pins.
| Signal | nRF5340 UART_0 - Serial Port 0 | nRF5340 UART_1 - Serial Port 1 |
|---|---|---|
| RTS | P0.11/TRACEDATA0 | P0.19 |
| TXD | P1.01 | P0.20 |
| CTS | P0.10/TRACEDATA1 | P0.21 |
| RXD | P1.00 | P0.22 |
Note: The serial ports on the nRF5340 DK PCB might be
incorrectly labeled. VCOM0 label on the PCB refers to serial port 0 and
VCOM2 refers to serial port 1.
The UART signals are routed directly to the interface MCU. The UART pins connected to the interface MCU are tri-stated when no terminal is connected to the virtual serial port on the computer. The terminal software must send a Data Terminal Ready (DTR) signal to configure the UART interface MCU pins.
P0.11/P0.19 (Request to Send (RTS)) and P0.10/P0.21 (Clear to Send (CTS)) can be used for other purposes when HWFC is disabled on the SoC.