Texas Instruments 3138 155 232931 - Manual (Page 44)

CC2420
SWRS041B Page 44 of 89
Wait for the specified crystal oscillator
start-up time, or poll the
XOSC16M_STABLE status bit
Power Down (PD)
[0]
SXOSCON
S
T
X
O
N
IDLE
[1]
Wait until voltage regulator
has powered up
Voltage Regulator Off VREG_EN set low
VREG_EN set high
Chip Reset
(pin or register)
All States
SXOSCOFF
command strobe
All States
except Power Down (PD)
SRFOFF
TX_CALIBRATE
[32]
All RX states
TX_PREAMBLE
[34, 35 and 36]
8 or 12 symbol
periods later
Preamble and SFD
is transmitted
TX_FRAME
[37, 38 and 39]
TXFIFO Data
is transmitted
RX_CALIBRATE
[2 and 40]
Tra
ns
m
issi
on
co
m
ple
te
d
S
R
X
O
N
RX_SFD_SEARCH
[3, 4, 5 and 6]
RX_FRAME
[16 and 40]
12 symbol periods
later
SFD
found Frame received or
failed address
recognition
Automatic or manual
acknowledge request
TX_ACK_CALIBRATE
[48]
12 symbol
periods later
TX_ACK_PREAMBLE
[49, 50 and 51]
TX_ACK
[52, 53 and 54]
Acknowledge
completed
RX_OVERFLOW
[17]
Crystal oscillator disabled,
register access enabled,
FIFO / RAM access disabled
S
T
X
O
N
o
r
(
S
T
X
O
N
C
C
A
a
n
d
C
C
A
)
SACK
o
r
SACK
PEND
RX_WAIT
[14]
TX_UNDERFLOW
[56]
Ov
erf
low
Underflow
SFLU
SHRX
The transition from
TX_UNDERFLOW to
RX_CALIBRATE is automatic,
but SFLUSHTX must be used to
reset underflow indication
Figure 25. Radio control states