Owner's manual

28
AT86RF211
1942C–WIRE–06/02
Notes: 1. The same ADC is used to measure RSSI or V
CC
voltage. When the V
CC
voltage is measured, the RSSI measurement is
stopped (previously measured RSSI is kept into STATUS Register). This can disturb the reception process (if a threshold is
used for DATAMSG validation). So, it is not recommended to measure V
CC
in reception mode.
2. V
CC
measurement can not be done when the AT86RF211 is in power-down mode.
3. While in V
CC
measurement, it is possible to measure the DC output of the discriminator.
4. Description of RSSI measurement with hysteresis mechanism: if the RSSI measurement is higher than the high RSSI level,
DATAMSG is validated (high RSSI level = TRSSI + HRSSI). If the RSSI measure is lower than the low RSSI level, DATA-
MSG is inhibited (low RSSI level = TRSSI - HRSSI). Between these two levels, DATAMSG validation depends on the
previous measurement.
Example:
TRSSI = 32 and HRSSI = 4 implies High RSSI level = 26 and Low RSSI level = 28
– 1 reserved, must be kept to reset value: 0
RXFS 2 RX frequency selection
(00)
2
:F0 (10)
2
:F2
(01)
2
: F1 (11)
2
:F3
reset value: (10)
2
XTALFQ 1 Crystal frequency
0: 10.245 MHz (when IF1 = 10.7 MHz)
1: 20.945 MHz (when IF1 = 21.4 MHz)
resetvalue:0
FSKBW 1 Discriminator range
0: Narrow Discriminator BW
1: Standard Discriminator BW
resetvalue:1
FSKPOL 1 Polarity of DATAMSG
0: inverted signal
1: direct signal
resetvalue:1
DSREF 1 Data Slicer reference voltage
0: external reference: SKFILT pin voltage
1: internal reference: DAC level voltage
resetvalue:1
– 1 reserved, must be kept to reset value: 0
– 1 reserved, must be kept to reset value: 0
MOFFSET 1 0: internal ADC sets to V
CC
measurement
1: internal ADC sets to DISCOUT DC level measurement
resetvalue:0
– 1 reserved, must be kept to reset value: 0
MRSSIsequence27323536353229282725
RSSI level NOK NOK NOK OK OK OK OK OK NOK NOK
DATAMSG valid valid valid valid valid
Table 6. CTRL1 Detailed Description
(1)(2)(4)(3)
(Continued)
Name
Number
of Bits Comments