CC2550_13 Datasheet, PDF (47/61 Pages) Texas Instruments – Low-Cost Low-Power 2.4 GHz RF Transmitter

CC2550
0x18: MCSM0 – Main Radio Control State Machine Configuration
Bit Field Name
Reset R/W Description
7:6 Reserved
5:4 FS_AUTOCAL[1:0]
3:2 PO_TIMEOUT
1:0 Reserved
0 (00)
2 (10)
R0
R/W Automatically calibrate when going to 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 TX (or FSTXON)
2 (10)
3 (11)
When going from TX back to IDLE
Every 4^th time when going from TX to IDLE
R/W Programs the number of times the six-bit ripple counter must expire
after XOSC has stabilized before CHP_RDYn goes low.
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
us.
If XOSC is off during power-down and the regulated digital supply
voltage has sufficient time to stabilize while waiting for the crystal to
be stable, PO_TIMEOUT can be set to 0. For robust operation it is
recommended to use PO_TIMEOUT=2.
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.
In order to reduce start up time from the SLEEP state, this field is
preserved in powerdown (SLEEP state).
R0 Defined in the transceiver version
0x22: FREND0 – Front End TX Configuration
Bit Field Name
Reset
R/W Description
7:6 Reserved
5:4 LODIV_BUF_CURRENT_TX[1:0]
1 (01)
3 Reserved
2:0 PA_POWER[2:0]
0 (000)
R0
R/W Adjusts current TX LO buffer (input to PA). The
value to use in this field is given by the SmartRF^®
Studio software [4].
R0
R/W Selects PA power setting. This value is an index to
the PATABLE. In OOK mode, this selects the
PATABLE index to use when transmitting a ‘1’.
PATABLE index zero is used in OOK when
transmitting a ‘0’.
SWRS039B
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