Rainbow Electronics ATmega128RFA1 - Manual (Page 35)

35
8266A-MCU Wireless-12/09
ATmega128RFA1
9.4 Operating Modes
9.4.1 Basic Operating Mode
This section summarizes all states to provide the basic functionality of the 2.4GHz radio
transceiver, such as receiving and transmitting frames, the power up sequence and
radio transceiver sleep. The Basic Operating Mode is designed for IEEE 802.15.4 and
ISM applications; the corresponding radio transceiver states are shown in
Figure 9-12
below .
Figure 9-12. Basic Operating Mode State Diagram (for timing refer to Table 9-3 on page 42 )
2
S
LP
TR
=
1
S
LP
TR
=
0
P
L L
_O
N
R X _ O N
P L L _ O N
T R X _ O F F
(C lo c k S ta te )
X O S C = O N
R
X
_O
N
S L E E P
(S le e p S ta te )
X O S C = O F F
F O R C E _ T R X _ O F F
(a ll s ta te s e x c e p t S L E E P )
S H R
D e te c te d
F ra m e
E n d
F r a m e
E n d
B U S Y _ T X
(T ra n s m it S ta te )
P L L _ O N
(P L L S ta te )
T X _ S T A R T
o r
TR
X
_O
FF
TR
X
_O
FF
3
4
5 7
6
8
9
1 1
1 0
1 2 1 3
T R X R S T = 0
F O R C E _ P L L _ O N
(a ll s ta te s e x c e p t S L E E P ,
T R X _ O F F )
1 4
S L P T R = 1
L e g e n d :
B lu e : R e g is te r w rite to T R X _ S T A T E
R e d : C o n tro l s ig n a ls v ia R e g is te r T R X P R
G r e e n : E v e n t
B a s ic O p e ra tin g M o d e S ta te s
S ta te tra n s itio n n u m b e r
R X _ O N
(R x L is te n S ta te )
B U S Y _ R X
(R e c e iv e S ta te )
R E S E T
( fro m a ll s ta te s )
T R X R S T = 1
X
Note: 1. State transition numbers correspond to Table 9-3 on page 42 .
9.4.1.1 State Control
The radio transceiver states are controlled either by writing commands to bits
TRX_CMD of register TRX_STATE, or directly by the two control bits SLPTR and
TRXRST of the TRXPR register. A successful state change can be verified by reading
the radio transceiver status from register TRX_STATUS.
If TRX_STATUS = 0x1F (STATE_TRANSITION_IN_PROGRESS) the radio transceiver
is on a state transition. Do not try to initiate a further state change while the radio
transceiver is in STATE_TRANSITION_IN_PROGRESS.