uart usable after softdevice disabled?

[Roland]

SDK v12, SD130 on 51822.

I init uart through APP_UART_FIFO_INIT, and installed uart_event_handler. UART rx/tx with an external MCU works OK while softdevice running.

then i tried to use sd_softdevice_disable() to disable softdevice. I expect uart to work as the same. However the uart turns out not responding anymore, either not receiving or sending anything.

Is it normal? Is uart related API and event handler still usable after softdevice disabled? any specific thing need to do to keep uart running?

thank you.

[Roland]

If the CPU was put in SYSTEM ON IDLE then as I am sure that external MCU is keeping sending data so the uart interrupt should wake CPU up? I also tried only stop advertising, instead of disable SD. the result is the same.

So i guess the CPU was actually put into SYSTEM OFF mode some how? But i do not know why that could happen.

PS: I forgot to mention i was running the code on custom board.