Rainbow Electronics ATmega128RFA1 - Manual (Page 41)

41
8266A-MCU Wireless-12/09
ATmega128RFA1
t
TR10
= 16 µs after initiating the transmission, the radio transceiver changes into
BUSY_TX state and the internally generated SHR is transmitted. After that the PSDU
data are transmitted from the Frame Buffer.
After completing the frame transmission, indicated by the TRX24_TX_END interrupt,
the PLL settles back to the receive frequency within t
TR11
= 32 µs in state PLL_ON.
If during TX_BUSY the radio transmitter is programmed to change to a receive state it
automatically proceeds the state change to RX_ON state after finishing the
transmission.
9.4.1.4.4 Reset Procedure
The radio transceiver reset procedure is shown in Figure 9-17 below .
Figure 9-17. Reset Procedure
x
E v e n t
S ta te
B lo c k
T im e [µ s ]
T R X R S T
T R X _ O F F
x + 4 0
[T R X 2 4 _ A W A K E IR Q ]
0
v a rio u s
T im e
3 x A V R c lo c k t
T R 1 3
> t1 1
X O S C , D V R E G e n a b le d X O S C , D V R E G e n a b le d
x + 1 0
F T N
Note: 1. Timing parameter t
TR13
= 37 µs refers to Table 9-3 on page 42; t
11
refers to "Digital
Interface Timing Characteristics" on page 507 .
2. If TRXRST is set during radio transceiver SLEEP state, the XOSC startup delay is
extended by the XOSC startup time.
TRXRST = “1” resets all radio transceiver registers to their default values.
The radio transceiver reset is released automatically after 3 AVR clock cycles and the
wake-up sequence without restarting XOSC and DVREG, nevertheless an FTN
calibration cycle is performed, refer to
"Automatic Filter Tuning (FTN)" on page 83. After
that the TRX_OFF state is entered.
Figure 9-17 above illustrates the radio transceiver reset procedure if the radio
transceiver is in any state but not in SLEEP state.
If the radio transceiver was in SLEEP state, the SLPTR bit in the TRXPR register must
be cleared prior to clearing the TRXRST bit in order to enter the TRX_OFF state.
Otherwise the radio transceiver enters the SLEEP state immediately.
If the radio transceiver was in SLEEP state and the Transceiver Clock is not selected as
the microcontroller clock source, the XOSC is enabled before entering TRX_OFF state.
If register TRX_STATUS indicates STATE_TRANSITION_IN_PROGRESS during
system initialization until the radio transceiver reaches TRX_OFF, do not try to initiate a
further state change while the radio transceiver is in this state.
Note that before accessing the radio transceiver module the TRX24_AWAKE event
should be checked.