I have a question related to the DW1000 example ex_05a_ds_twr_init. In the message response, the code looks like this:
/* Retrieve poll transmission and response reception timestamp. */ poll_tx_ts = get_tx_timestamp_u64(); resp_rx_ts = get_rx_timestamp_u64(); /* Compute final message transmission time. See NOTE 10 below. */ final_tx_time = (resp_rx_ts + (RESP_RX_TO_FINAL_TX_DLY_UUS * UUS_TO_DWT_TIME)) >> 8; dwt_setdelayedtrxtime(final_tx_time); /* Final TX timestamp is the transmission time we programmed plus the TX antenna delay. */ final_tx_ts = (((uint64)(final_tx_time & 0xFFFFFFFEUL)) << 8) + TX_ANT_DLY;
My question is: What is the purpose of masking with 0xFFFFFFFEUL. Why is it necessary to make the last bit 0?
Thank you in advance!