116
8168C-MCU Wireless-02/10
AT86RF212
the supply voltage is below the default 1.8 V threshold at power up (BATMON_OK
was never 1), or
a new threshold is set which is still above the current supply voltage (BATMON_OK
remains 0).
When the battery voltage is close to the programmed threshold voltage, noise or
temporary voltage drops may generate unwanted interrupts. To avoid this,
disable the IRQ_7 (BAT_LOW) in register 0x0E (IRQ_MASK) and treat the battery as
empty, or
set a lower threshold value.
7.6.5 Register Description
Register 0x11 (BATMON):
This register configures the battery monitor to compare the supply voltage at pin 28
(EVDD) to the threshold. Additionally, the supply voltage status at pin 28 (EVDD) can
be read from register bit BATMON_OK according to the actual BATMON settings.
Table 7-23. Register 0x11 (BATMON)
Bit
7
6
5
4
Name
PLL_LOCK_CP
Reserved
BATMON_OK
BATMON_HR
Read/Write
R
R/W
R
R/W
Reset Value
0
Bit
3
2
1
0
Name
BATMON_VTH[3]
BATMON_VTH[2]
BATMON_VTH[1]
BATMON_VTH[0]
Read/Write
R/W
Reset Value
0
1
0
Bit 7 – PLL_LOCK_CP
Bit 6 – Reserved
Bit 5 – BATMON_OK
The register bit BATMON_OK indicates the level of the external supply voltage with
respect to the programmed threshold BATMON_VTH.
Table 7-24. Battery Monitor Status
Register Bit
Value
Description
0
The battery voltage is below the threshold.
BATMON_OK
1
The battery voltage is above the threshold.
Bit 4 – BATMON_HR
The register bit BATMON_HR sets the range and resolution of the battery monitor.
Table 7-25. Battery Monitor Range Selection
Register Bit
Value
Description
0
Enables the low range, see BATMON_VTH
BATMON_HR
1
Enables the high range, see BATMON_VTH