MRF49XAT-I-ST Datasheet, PDF (60/102 Pages) Microchip Technology – ISM Band Sub-GHz RF Transceiver

MRF49XA
TABLE 3-2: DIGITAL RSSI THRESHOLD LEVELS
RSSI Threshold
DRSSIT2
Reserved
1
Reserved
1
-73
1
-79
1
-85
0
-91
0
-97
0
-103
0
DRSSIT1
1
1
0
0
1
1
0
0
FIGURE 3-11:
INPUT POWER VS. ANALOG RSSI VOLTAGE
-1 12
-102
-9 2
-82
-72
-62
-52
Input Power (dBm)
DRSSIT0
1
0
1
0
1
0
1
0
1.2
1
0.8
0.6
0.4
0.2
0
-42
3.13.1 RELATIONSHIP BETWEEN RSSI
AND CLOCK RECOVERY
The DIO signal response time setting is configured
through RXCREG and has the following modes of
operation:
• Normal mode
• Slow mode
• Medium mode
• Fast mode
These operation modes are configurable through
BBFCREG.
In Medium mode, the DIO signal is active when the
CR_LOCK and the DRSSI or the DQI signals are high.
The DIO goes low when either the CR_LOCK turns
inactive, or the DRSSI or DQI signals go low. For more
details on DQI, see Section 3.11, Data Quality
Indicator.
3.13.2 RELATIONSHIP BETWEEN RSSI
AND AFC
The Keep Offset mode of automatic configuration of
AFC (i.e., AUTOMS1 = 1, AUTOMS0 = 1) is
recommended to be used when a receiver operates
with only one transmitter. After a complete measuring
cycle, the measured value is kept independent from
the state of the DIO signal. In this mode, the DRSSI
limit should be carefully selected to minimize the range
hysteresis.
The registers associated with RSSI are:
• STSREG (see Register 2-1)
• GENCREG (see Register 2-2)
• RXCREG (see Register 2-7)
• PMCREG (see Register 2-13)
DS70590C-page 60
Preliminary
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