Oki ML63611, User Manual

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ML63611 User’s Manual
Chapter 14 Battery Low Detect Circuit (BLD)
14 – 2
OPTION B (D): 1.5 V (3.0 V), With regulator
circuit for LCD bias
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
14.3 Judgment Voltage
The value of the judgment voltage is selected by the software by setting the LD1 (bit 1 of BLDCON) and LD0 (bit
0 of BLDCON) bits.
Table 14-1 lists judgment voltage and precision values.
Table 14-1 Judgment Voltage
LD1 LD0 Judgment voltage (V) Precision (V) Remarks
0 0 1.8 ±0.1 Ta = 25°C
0 1 2.0 ±0.1 Ta = 25°C
1 0 2.4 ±0.1 Ta = 25°C
1 1 2.6 ±0.1 Ta = 25°C
14.4 Battery Low Detect Circuit Register
•
Battery low detect control register (BLDCON)
BLDCON is a 4-bit special function register (SFR) that controls the battery low detect circuit.
bit 3: BLDF
This flag indicates the judgment result of the battery low detect circuit.
This bit is set to “1” when V
DD
is lower than the judgment voltage selected by LD0 and LD1, and
is set to “0” when V
DD
is higher. This bit is “0” when the BLD circuit stops operation.
This bit is read-only and writes are invalid.
bit 2: ENBL
This bit turns the battery low detect circuit ON or OFF.
When ENBL is set to “1”, the battery low detect circuit is ON. When ENBL is set to “0”, the
battery low detect circuit is OFF.
At system reset, this bit is cleared to “0”.
bit 1, 0: LD1, LD0
These bits select the judgment voltage.
At system reset, these bits are cleared to “0”.
BLDF ENBL LD1
LD0
Judgment result flag
0: Higher than judgment value (initial value)
1: Lower than judgment value
BLDCON (094H)
(R/W)
bit 3 bit 2 bit 1 bit 0
Judgment voltage select
bit 1 bit 0
0 0 : 1.8 ±0.1 V (initial value)
0 1 : 2.0 ±0.1 V
1 0 : 2.4 ±0.1 V
1 1 : 2.6 ±0.1 V
Battery low detect circuit ON/OFF control
0: Battery low detect circuit OFF (initial value)
1: Battery low detect circuit ON