Posts: 417
Registered: ‎07-13-2015
Accepted Solution

EFM32 half-duplex UART hardware question



I'd like to use the UART peripherials in an EFM32WG980 chip in async half-duplex mode. According to the reference manual, this is possible and works in such a way that the TX pin is used for both sending and receiving.


My question is, when using the peripherials in this configuration, do I need to externally connect the TX and RX pins on my PCB? If not, can I use the RX pin for something else entirely? (For example, another communication port or a GPIO or whatever.)


I'm interested in learning the answer to this in the context of all UART peripherials, ie. not only UART but also LEUART and USART. Thanks in advance for your answers!

Posts: 273
Registered: ‎03-03-2015

Re: EFM32 half-duplex UART hardware question

Hi Timur,


When using loopback mode, the pin that would be used for RX is not connected to the peripheral and may be used for other things, such as GPIO.  This applies to UART, USART and LEUART on the WG.