UART low power wakeup time

[Rushd]

Hello, I m using the UART in low power flow control mode(app_uart library). When the CTS line is asserted, what is the maximum time that the UART module takes for the UART to be powered up and ready to receive the first data byte considering the chip is in sleep mode waiting for events(sd_app_evt_wait)? I m using it at 9600 bps baud rate with softdevice S130, SDK 8.1.

[Rushd]

Guys. Any hint or guidance??

[Rushd]

I was able to get the following response through the support case:

"The main delay is the startup time of the HFCLK,which is typically 800us according to spec (table 22, nRF51 PS). The SW overhead for enabling RX seems to be very small in comparison to this delay: trigger on pin change -> set enable and start task register in UART module.

If you have a logic analyzer I think you should get a more accurate measure for your setup. Just measure the time between a CTS assert and a RTS assert. "