uart disable&enable damages uart on nrf9160

[MosheSmartAmr]

hi all,

i'm using uart with easyDMA, and i'm disabling and enabling it back on my code.
before disabling the uart TX and RX works fine. after disable&enable i get wrong data on RX.
what i get on RX is always the same bytes, even after restarting the device. it is very odd.

here is how i disable:

1727       NRF_UARTE0->TASKS_STOPTX = 1;
1728       NRF_UARTE0->TASKS_STOPRX = 1;
1729 
1730       NRF_UARTE1->TASKS_STOPTX = 1;
1731       NRF_UARTE1->TASKS_STOPRX = 1;

enable seq:

1741         NRF_UARTE0->TASKS_STARTRX = 1;
1742         NRF_UARTE1->TASKS_STARTRX = 1;

am i doing anything wrong? is there something i'm missing?

thanks in advance.

[Håkon Alseth]

Hi,

 

When issuing STOPRX, you should wait for the RXTO event, as described here, before disabling the peripheral:

https://infocenter.nordicsemi.com/topic/ps_nrf9160/uarte.html?cp=2_0_0_5_18_6#concept_twi_low_power

After this event has occurred, you can potentially have received a transaction, which can check via the ENDRX event (or FLUSHRX if you're not interested at that point). I do not know how the rest of the logic is here, but if you also have disabled interrupts prior to disabling the receiver, it is potentially a payload that has been transferred from the previous run.

 

Kind regards,

Håkon