RTT logger behavior upon disconnected debug port

Question

Hi, 
 I am using RTT log with nRF52832, my question is when debug port is disconnected, what will happen to RTT logger? 
 Will they be simply ignored? or will the debug pins will still have signal outputs? 
 My wish is that there will be no high/low level changes at both SWIO and SWCLK pins when they are disconnected --- even if the app uses NRF_LOG_INFO() to emit logs. 
 Regards, 
 yf13

Simon · Accepted Answer

If the host is not active when writing to RTT, data will not be written. Take a look at the explanatory text above serial_tx( ) in nrf_log_backend_rtt.c: 
 /* There are two possible reasons for not writing any data to RTT:
 * - The host is not connected and not reading the data.
 * - The buffer got full and will be read by the host.
 * These two situations are distinguished using the following algorithm.
 * At the begining, the module assumes that the host is active,
 * so when no data is read, it busy waits and retries.
 * If, after retrying, the host reads the data, the module assumes that the host is active.
 * If it fails, the module assumes that the host is inactive and stores that information. On next
 * call, only one attempt takes place. The host is marked as active if the attempt is successful.
 */ 
 Best regards, 
 Simon

RTT logger behavior upon disconnected debug port

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