ISL12020MIRZ-T7A Datasheet, PDF (15/34 Pages) Intersil Corporation – Low Power RTC with Battery Backed SRAM, Integrated ±5ppm Temperature Compensation and Auto Daylight Saving

ISL12020M
TABLE 1. REGISTER MEMORY MAP (X INDICATES DEFAULT VARIES WITH EACH DEVICE. YELLOW SHADING INDICATES THOSE BITS SHOULD NOT BE
CHANGED BY THE USER) (Continued)
BIT
REG
ADDR. SECTION NAME
7
6
5
4
3
2
1
0
RANGE DEFAULT
20h DSTCR DstMoFd DSTE
D
D
DstMoFd DstMoFd DstMoFd DstMoFd DstMoFd 1 to 12
00h
20
13
12
11
10
21h
DstDwFd
D
DstDwFd DstWkFd DstWkFd DstWkFd DstDwFd DstDwFd DstDwFd 0 to 6
00h
E
12
11
10
12
11
10
22h
DstDtFd
D
D
DstDtFd2 DstDtFd2 DstDtFd1 DstDtFd1 DstDtFd1 DstDtFd1 1 to 31
00h
1
0
3
2
1
0
23h
DstHrFd
D
D
DstHrFd2 DstHrFd2 DstHrFd1 DstHrFd1 DstHrFd1 DstHrFd1 0 to 23
00h
1
0
3
2
1
0
24h
DstMoRv
D
D
D
XDstMoR DstMoRv DstMoR1 DstMoRv DstMoRv 01 to 12
00h
v20
13
2v
11
10
25h
DstDwRv
D
DstDwRv DstWkrv1 DstWkRv DstWkRv DstDwRv DstDwRv DstDwRv 0 to 6
00h
E
2
11
10
12
11
10
26h
DstDtRv
D
D
DstDtRv2 DstDtRv2 DstDtRv1 DstDtRv1 DstDtRv1 DstDtRv1 01 to 31
00h
1
0
3
2
1
0
27h
DstHrRv
D
D
DstHrRv2 DstHrRv2 DstHrRv1 DstHrRv1 DstHrRv1 DstHrRv1 0 to 23
00h
1
0
3
2
1
0
28h
TEMP
TK0L
TK07
TK06
TK05
TK04
TK03
TK02
TK01
TK00 00 to FF
00h
29h
TK0M
0
0
0
0
0
0
TK09
TK08 00 to 03 00h
2Ah
NPPM NPPML NPPM7 NPPM6 NPPM5 NPPM4 NPPM3 NPPM2 NPPM1 NPPM0 00 to FF
00h
2Bh
NPPMH
0
0
0
0
0
NPPM10 NPPM9 NPPM8 00 to 07
00h
2Ch
XT0
XT0
D
D
D
XT4
XT3
XT2
XT1
XT0
00 to FF
XXh
2Dh ALPHAH ALPHAH
D
ALP_H6 ALP_H5 ALP_H4 ALP_H3 ALP_H2 ALP_H1 ALP_H0 00 to 7F
XXh
2Eh
GPM
GPM1 GPM17 GPM16 GPM15 GPM14 GPM13 GPM12 GPM11 GPM10 00 to FF
00h
2Fh
GPM2 GPM27 GPM26 GPM25 GPM24 GPM23 GPM22 GPM21 GPM20 00 to FF
00h
Real Time Clock Registers
Addresses [00h to 06h]
RTC REGISTERS (SC, MN, HR, DT, MO, YR, DW)
These registers depict BCD representations of the time. As such,
SC (Seconds) and MN (Minutes) range from 0 to 59, HR (Hour)
can either be a 12-hour or 24-hour mode, DT (Date) is 1 to 31,
MO (Month) is 1 to 12, YR (Year) is 0 to 99, and DW (Day of the
Week) is 0 to 6.
The DW register provides a Day of the Week status and uses three
bits DW2 to DW0 to represent the seven days of the week. The
counter advances in the cycle 0-1-2-3-4-5-6-0-1-2-…
The assignment of a numerical value to a specific day of the
week is arbitrary and may be decided by the system software
designer. The default value is defined as “0”.
24-HOUR TIME
If the MIL bit of the HR register is “1”, the RTC uses a 24-hour
format. If the MIL bit is “0”, the RTC uses a 12-hour format and
HR21 bit functions as an AM/PM indicator with a “1”
representing PM. The clock defaults to 12-hour format time with
HR21 = “0”.
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 and the year 2100 is not. The ISL12020M does not
correct for the leap year in the year 2100.
Control and Status Registers
(CSR)
Addresses [07h to 0Fh]
The Control and Status Registers consist of the Status Register,
Interrupt and Alarm Register, Analog Trimming and Digital
Trimming Registers.
Status Register (SR)
The Status Register is located in the memory map at address
07h. This is a volatile register that provides either control or
status of RTC failure (RTCF), Battery Level Monitor (LBAT85,
LBAT75), alarm trigger, Daylight Saving Time, crystal oscillator
enable and temperature conversion in progress bit.
15
FN6667.5
December 13, 2011