isl12057 Intersil Corporation, isl12057 Datasheet - Page 9

• Manufacturer Part Number: isl12057
• Description: Low Cost And Low Power I 2c Rtc Real Time Clock/calendar
• Manufacturer: Intersil Corporation

Real Time Clock Registers
Addresses [00h to 06h]
RTC REGISTERS (SC, MN, HR, DW, DT, MO, YR)
These registers depict BCD representations of the time. As
such, SC (Seconds, address 00h) and MN (Minutes,
address 01h) range from 0 to 59, HR (Hour, address 02h)
can either be a 12-hour or 24-hour mode, DW (Day of the
Week, address 03h) is 1 to 7, DT (Date, address 04h) is 1 to
31, MO (Month, address 05h) is 1 to 12, and YR (Year,
address 06h) is 0 to 99.
The DW register provides a Day of the Week status and uses
3 bits DW2 to DW0 to represent the seven days of the week.
The counter advances in the cycle 1-2-3-4-5-6-7-1-2-…
The assignment of a numerical value to a specific day of the
week is arbitrary and may be decided by the system
software designer.
24-HOUR TIME
If the MIL bit of the HR register is “0”, the RTC uses a
24-hour format and bit 5 of the HR register is the second
10-hour bit (20–23 hours). If the MIL bit is “1”, the RTC uses
a 12-hour format and bit 5 of the HR register is the AM/PM
ADDR SECTION
0Ch
0Dh
00
01
02
03
04
05
06h
07h
08h
09h
0Ah
0Bh
0Eh
0Fh
H
H
H
H
H
H
Alarm1
Alarm2
Control
Status
RTC
A1DW/
A2DW/
NAME
A1MN
A1HR
A2MN
A2HR
A1SC
REG
DW
MO
INT
MN
SC
HR
DT
YR
DT
DT
SR
C
EOSC
A1M1
A1M2
A1M3
A1M4
A2M2
A2M3
A2M4
YR23
ENTUR
OSF
9
0
0
0
0
0
Y
7
A1DW/DT
A2DW/DT
A1MN22
A2MN22
A1SC22
A1MIL
A2MIL
MN22
SC22
YR22
MIL
6
0
0
0
0
0
TABLE 1. REGISTER MEMORY MAP
A1AM/PM
A2AM/PM
A1MN21
A1HR21
A2MN21
A2HR21
A1SC21
A1DT21
A2DT21
AM/PM
MN21
SC21
HR21
DT21
YR21
5
0
0
0
0
0
0
ISL12057
A1MN20
A2MN20
A1SC20
A1HR20
A2HR20
A1DT20
A2DT20
MO20
MN20
HR20
SC20
DT20
YR20
RS2
4
0
0
0
0
BIT
A1MN13
A2MN13
A1SC13
A1HR13
A2HR13
bit with logic high being PM. The clock defaults to 24-hour
format time.
CENTURY INDICATOR
The century bit (bit 7 of the MO register) is toggled when the
years register overflows from 99 to 00 to indicator the
change of century.
LEAP YEARS
Leap years add the day February 29 and are defined as those
years that are divisible by 4. Years divisible by 100 are not leap
years, unless they are also divisible by 400. This means that
the year 2000 is a leap year, the year 2100 is not. The
ISL12057 does not correct for the leap year in the year 2100.
Addresses [0Eh to 0Fh]
The Control and Status Registers consist of the Status
Register, Interrupt and Alarm Register.
A1DT13
A2DT13
MN13
MO13
HR13
SC13
DT13
YR13
RS1
3
0
0
0
0
A1DW12
A2DW12
A1MN12
A2MN12
A1SC12
A1HR12
A2HR12
A1DT12
A2DT12
INTCN
MN12
DW12
MO12
SC12
HR12
YR12
DT12
2
0
A1MN11
A1DW11
A2MN11
A2DW11
A1SC11
A1HR11
A2HR11
A1DT11
A2DT11
DW11
MO11
MN11
HR11
SC11
DT11
YR11
A2IE
A2F
1
A1DW10
A2DW10
A1MN10
A1HR10
A2MN10
A2HR10
A1SC10
A1DT10
A2DT10
DW10
MN10
MO10
SC10
HR10
DT10
YR10
A1IE
A1F
0
+Century
+AM/PM
+AM/PM
+AM/PM
RANGE
0-59
0-59
1-12
0-23
1-31
0-12
0-99
0-59
0-59
1-12
0-23
1-31
0-59
1-12
0-23
1-31
N/A
N/A
1-7
1-7
1-7
REG
June 15, 2009
DEFAULT
FN6755.0
00h
00h
00h
01h
01h
00h
00h
00h
00h
00h
00h
00h
00h
18h
80h
01h
00h
00h