MRF24J40_08 Datasheet, PDF (116/152 Pages) Microchip Technology – IEEE 802.15.4™ 2.4 GHz RF Transceiver

MRF24J40
3.14 Battery Monitor
The MRF24J40 provides a battery monitor feature to
monitor the system supplied voltage. A threshold volt-
age level (BATTH) can be set and the system supplied
voltage can be monitored by the Battery Low Indicator
(BATIND) to determine if the voltage is above or below
the threshold. The following steps set the threshold and
enable battery monitoring:
1. Set the battery monitor threshold (BATTH)
voltage in the RFCON5 (0x205<7:4>) register.
2. Enable battery monitoring by setting BATEN = 1
in the RFCON6 (0x206<3>) register.
3. Periodically, monitor the Battery Low Indicator
(BATIND) bit in the RXSR (0x30<5>) register to
determine if the system supply voltage is above
or below the battery monitor threshold (BATTH).
TABLE 3-18: REGISTERS ASSOCIATED WITH POWER MANAGEMENT
Addr. Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
0x30 RXSR
r
UPSECERR BATIND
r
r
r
0x205 RFCON5 BATTH3 BATTH2 BATTH1 BATTH0
r
r
0x206 RFCON6 TXFIL
r
r
20MRECVR BATEN
r
Bit 1
r
r
r
Bit 0
r
r
r
DS39776B-page 114
Preliminary
© 2008 Microchip Technology Inc.