The debugger has two virtual serial ports. Each of them has a Universal Asynchronous Receiver/Transmitter (UART) interface.
- Flexible baud rate setting up to 1 Mbps (baud rate 921,600 bps is not supported)
- Optional Hardware Flow Control (HWFC) pins
- Automatic detection of HWFC if flow control pins are connected
- Tri-stated UART lines when no terminal is connected
The following table lists the nRF54L15 SoC's UART GPIO pins and their signals.
| Signal | nRF54L15 SoC UART_0 - Serial Port 0 | nRF54L15 SoC UART_1 - Serial Port 1 |
|---|---|---|
| TXD | P0.00 | P1.04 |
| RXD | P0.01 | P1.05 |
| RTS | P0.02 | P1.06 |
| CTS | P0.03 | P1.07 |
The UART pins connected to the debugger 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 debugger UART pins.
P0.02/P1.06 Request to Send (RTS) and P0.03/P1.07 Clear to Send (CTS) can be used for other purposes when HWFC is disabled on the nRF54L15 SoC.
The UART signals are routed to the debugger through analog switches U4 and U5.
UART pins for other tasks
For each UART instance, the TXD/RXD signals can be disconnected from the debugger as a group. For the UARTs in use, the RTS/CTS signals can be connected and disconnected from the debugger as a group depending on the HWFC usage. This can be done through nRF Connect for Desktop's Board Configurator application.