Specifications

CC1101
SWRS061I Page 82 of 98
0x18: MCSM0– Main Radio Control State Machine Configuration
Bit
Field Name
Reset
R/W
Description
7:6
R0
Not used
5:4
FS_AUTOCAL[1:0]
0 (00)
R/W
Automatically calibrate when going to RX or TX, or back to IDLE
Setting
When to perform automatic calibration
0 (00)
Never (manually calibrate using SCAL strobe)
1 (01)
When going from IDLE to RX or TX (or FSTXON)
2 (10)
When going from RX or TX back to IDLE
automatically
3 (11)
Every 4
th
time when going from RX or TX to IDLE
automatically
In some automatic wake-on-radio (WOR) applications, using setting 3 (11)
can significantly reduce current consumption.
3:2
PO_TIMEOUT
1 (01)
R/W
Programs the number of times the six-bit ripple counter must expire after
XOSC has stabilized before CHP_RDYn goes low
[1]
.
If XOSC is on (stable) during power-down, PO_TIMEOUT should be set so that
the regulated digital supply voltage has time to stabilize before CHP_RDYn
goes low (PO_TIMEOUT=2 recommended). Typical start-up time for the
voltage regulator is 50 μs.
For robust operation it is recommended to use PO_TIMEOUT = 2 or 3 when
XOSC is off during power-down.
[1]
Note that the XOSC_STABLE signal will be asserted at the same time as
the CHP_RDYn signal; i.e. the PO_TIMEOUT delays both signals and does not
insert a delay between the signals
Setting
Expire count
Timeout after XOSC start
0 (00)
1
Approx. 2.3 – 2.4 μs
1 (01)
16
Approx. 37 – 39 μs
2 (10)
64
Approx. 149 – 155 μs
3 (11)
256
Approx. 597 – 620 μs
Exact timeout depends on crystal frequency.
1
PIN_CTRL_EN
0
R/W
Enables the pin radio control option
0
XOSC_FORCE_ON
0
R/W
Force the XOSC to stay on in the SLEEP state.