CC2550_06 Datasheet, PDF (44/55 Pages) Texas Instruments – Single Chip Low Cost Low Power 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.
The XOSC is off during power-down so the regulated digital supply
voltage has time to stabilize while waiting for the crystal to be stable
even with PO_TIMEOUT to 0.
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 on 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.
R0
R/W Selects PA power setting. This value is an index to
the PATABLE, which can be programmed with up to
8 different PA settings. The PATABLE settings from
index ‘0’ to the PA_POWER value are used for
power ramp-up/ramp-down at the start/end of
transmission in all TX modulation formats.
PRELIMINARY Data Sheet (Rev.1.2) SWRS039A
Page 44 of 54