Samsung SC32442B54, User Manual

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REAL TIME CLOCK SC32442B RISC MICROPROCESSOR
17-10
BCD YEAR (BCDYEAR) REGISTER
Register Address R/W Description Reset Value
BCDYEAR 0x57000088(L)
0x5700008B(B)
R/W
(by byte)
BCD year register Undefined
BCDYEAR Bit Description Initial State
YEARDATA [7:0] BCD value for year.
00 ~ 99 -
RTC LOWBAT CHECK (RTCLBAT) REGISTER
Register Address R/W Description Reset Value
RTCLBAT 0x5700006C(L)
0x5700006F(B) R/W
(by byte)
RTC Low Battry Check register -
RTCBAT Bit Description Initial State
LOWBAT [0] 1: Clear Low Battery register.
-
Note)
1. This is the bit for detecting low voltage. When the power source’s voltage drops below 1.3V(max). This flag is
set to “1”. After the initial power on, it is set to 1. If this flag is set to 1 enter recovery from the backup state. This
means during the backup the power was low, and all data need to be initialized.
(1) LOWBAT = “1” as result of initial supply of power
(2) If LOWBAT bit is “1” clear the bit to “0” after checking the RTCLBAT register.
(3) When the power supply is low but voltage is not dropping to 1.3V, LOWBAT bit remained “0” with no
change
(4) When the power supply is low and voltage dropping below 1.3V, VL becames “1”
(5) If LOWBAT bit is “1” clear the bit to “0” after checking the RTCLBAT register.
2. The register related to RTC did not reset by Power-On Reset when the RTC power supply keep the voltage
above the VDDrtc minimum spec.