ACE5372_11 Datasheet, PDF (4/31 Pages) ACE Technology Co., LTD. – Low Power Real-Time Clock (RTC)

ACE5372
Low Power Real-Time Clock (RTC)
7H
Time Trimming Register
Storing adjusting parameter and external select control of
crystal oscillator
Alarm_A (Minute
8H
Register)
Storing minutes in Timer A
9H
Alarm_A (Hour Register)
Storing hours in Timer A
AH
Alarm_A (Day of the
Week Register)
Alarm_B (Minute
BH
Register)
Storing days of the week in Timer A
Storing minutes in Timer B
CH
Alarm_B (Hour Register)
Storing hours in Timer B
DH
Alarm_B (Day of the
Week Register)
Storing days of the week in Timer B
Storing ring enable, interrupt output port select, and periodic
EH
Control Register 1
interrupt cycle select information
Storing time display select, interrupt and alarm signal,
FH
Control Register 2
oscillator halt sensing information
Calendar Counter
The ACE5372 can exchange from year to second (lower two bits) with CPU. When the lower two bits of
the year could be divided by 4, that year is leap year. It could automatically recognize the year between
2000 and 2099 and these data are stored separately in registers from 0H to 6H.
Control Unit
The control unit is a substantial part of the ACE5372, under which all functionalities of the whole circuit is
realized. The time display select, interrupt / alarm select and signal, output port select, as well as
oscillation halt sensing information are all sent out by the control circuit.
High Precision time Trimming function
The ACE5372 has an internal oscillation circuit capacitance CGND and CVDD so that an oscillation
circuit may be configured simply by externally connecting a crystal. The ACE5372 incorporates a time
trimming circuit (at internal address 7H) that adjusts gain or loss of the clock from the CPU up to
approx.±189ppm(±194ppm when 32.000KHz crystal is used) by approximately 3ppm steps to correct
discrepancy in oscillation frequency.
*Clock display is possible at much higher precision than conventional real-time clock while using a
crystal with broader fluctuation in precision.
* Even seasonal frequency fluctuation may be corrected by adjusting seasonal clock error.
For those systems that have temperature detection precision of clock, function may be increased by
correcting clock error according to temperature fluctuations.
VER 1.3 4