Chipcon CC400DB, Руководство пользователя

Страница: 11 / 19

SWRU068
11
However, if it is an acknowledgement packet that is received, the message is only shown
on the LED without any reply.
3.5 Data reception
The data reception algorithm is as follows:
1.
Enter RX precharge mode, wait
2. Enter RX mode
3. The receiver shall receive synchronisation pattern (pre-amble) for some periods
before it is allowed to detect SOF
4. Wait for SOF
5. Receive and decode data
6. Display data on LED
3.6 Data decoder algorithm
The decoder algorithm implemented is based on oversampling. Each bit is sampled 8
times, and the data decision is based on a majority vote. The use of oversampling makes
the data decision more immune to noise and duty cycle variations than a data decision
algorithm based entirely on detecting edges.
The oversampling algorithm synchronises on the preamble, and thereafter continues to
synchronise itself by detecting edges.
For more information on oversampling, see application note AN008 : Oversampling and
data decision.