User's Manual

Figure 4: Wake-up from standby

9.2.2 Wake-up latency from shutdown

The wake-up time from shutdown is 5 ms.

Figure 5: Wake-up from shutdown

9.3 Latencies during data transfer / packet generation

The data transfer is always buffered, i.e. data received via UART is buffered in the module

until a speciﬁc event occurs (i.e. packet completed with the CS ﬁeld of a command). Subse-

quently, the UART reception is interrupted (ﬂow control with /RTS signal), and the payload

data is passed to the internal memory of the wireless transceiver (FIFO).

By using several UART buffers the time during which the UART is not receiving can be min-

imized.

The wireless transmission starts as soon as the ﬁrst complete data packet is available in the

transceiver memory. During the continuous wireless transmission, the remaining payload

data is transmitted byte by byte on the radio. On the receiver side, the buffer is read as soon

as an incoming packet is detected. The entire radio frame is buffered in the radio buffer and

processed once the frame was checked against bit errors.

If the module detects a packet that requires an ACK, the ACK is sent directly after the full

packet reception. The channel access method is always deactivated for any ACKs.