Here’s a program that drives the UART via a Silicon Labs USB to UART Bridge connected to putty.
Video shows me starting the program and getting a prompt.
I type in characters which are echoed back from the Nordic. Then I press ‘q’ which causes it spew characters out as fast as it can.
/**********************************************************************
* MIK’s version operates at 115K2 RTS/CTS 8N1
**********************************************************************/