ISL12020MIRZ-T7A Datasheet, PDF (24/34 Pages) Intersil Corporation – Low Power RTC with Battery Backed SRAM, Integrated ±5ppm Temperature Compensation and Auto Daylight Saving

ADDRESS
20h
21h
22h
23h
FUNCTION
Month Forward
Day Forward
Date Forward
Hour Forward
7
DSTE
0
0
ISL12020M
TABLE 22. DST FORWARD REGISTERS
6
5
4
3
0
0
MoFd20
MoFd13
DwFdE
WkFd12
WkFd11
WkFd10
0
DtFd21
DtFd20
DtFd13
0
HrFd21
HrFd20
HrFd13
2
MoFd12
DwFd12
DtFd12
HrFd12
1
MoFd11
DwFd11
DtFd11
HrFd11
0
MoFd10
DwFd10
DtFd10
HrFd10
ADDRESS
NAME
7
24h
Month Reverse
0
25h
Day Reverse
0
26h
Date Reverse
0
27h
Hour Reverse
TABLE 23. DST REVERSE REGISTERS
6
5
4
3
0
0
MoRv20
MoRv13
DwRvE
WkRv12 WkRv11 WkRv10
0
DtRv21
DtRv20
DtRv13
0
HrRv21
HrRv20
HrRv13
2
MoRv12
DwRv12
DtRv12
HrRv12
1
MoRv11
DwRv11
DtRv11
HrRv11
0
MoRv10
DwRv10
DtRv10
HrRv10
• Bits 0, 1, 2 contain the Day of the week information, which
sets the Day of the Week that DST starts. Note that Day of the
week counts from 0 to 6, like the RTC registers. The default for
the DST Forward Day of the Week is 00h (normally Sunday).
• Bits 3, 4, 5 contain the Week of the Month information that
sets the week that DST starts. The range is from 1 to 5, and
Week 7 is used to indicate the last week of the month. The
default for the DST Forward Week of the Month is 00h.
DST Date Forward
DstDtfd controls which Date DST begins. The format for the Date
is the same as for the RTC register, from 1 to 31. The default
value for DST forward date is 00h. DstDtFd is only effective if
DstDwFdE = 0.
DST Hour Forward
DstHrFd controls the hour that DST begins. The RTC hour and
DstHrFd registers have the same formats except there is no
Military bit for DST hour. The user sets the DST hour with the
same format as used for the RTC hour (AM/PM or MIL) but
without the MIL bit, and the DST will still advance as if the MIL bit
were there. The default value for DST hour Forward is 00h.
DST REVERSE REGISTERS (24H TO 27H)
DST end (reverse) is controlled by the following DST Registers:
DST Month Reverse
DstMoRv sets the Month that DST ends. The format is the same
as for the RTC register month, from 1 to 12. The default value for
the DST end month is October (10h).
DST Day/Week Reverse
DstDwRv contains both the Day of the Week and the Week of the
Month data for DST Reverse control. DST can be controlled either
by actual date or by setting both the Week of the month and the
Day of the Week. DstDwRvE sets the priority of the Day/Week
over the Date. For DstDwRvE = 1, Day/Week is the priority. You
must have the correct Day of Week entered in the RTC registers
for the Day/Week correction to work properly.
• Bits 0,1,2 contain the Day of the week information, which sets
the Day of the Week that DST ends. Note that Day of the week
counts from 0 to 6, like the RTC registers. The default for the
DST Reverse Day of the Week is 00h (normally Sunday).
• Bits 3, 4, 5 contain the Week of the Month information that sets
the week that DST ends. The range is from 1 to 5, and Week 7 is
used to indicate the last week of the month. The default for the
DST Reverse Week of the Month is 00h.
DST Date Reverse
DstDtRv controls which Date DST ends. The format for the Date is
the same as for the RTC register, from 1 to 31. The default value
for DST Date Reverse is 00h. The DstDtRv is only effective if the
DwRvE = 0.
DST Hour Reverse
DstHrRv controls the hour that DST ends. The RTC hour and
DstHrFd registers have the same formats except there is no
Military bit for DST hour. The user sets the DST hour with the
same format as used for the RTC hour (AM/PM or MIL) but
without the MIL bit, and the DST will still advance as if the MIL bit
were there. The default value for DST hour Reverse is 00h.
TEMP Registers (TEMP)
The temperature sensor produces an analog voltage output
which is input to an A/D converter and produces a 10-bit
temperature value in degrees Kelvin. TK07:00 are the LSBs of the
code, and TK09:08 are the MSBs of the code. The temperature
result is actually the average of two successive temperature
measurements to produce greater resolution for the temperature
control. The output code can be converted to degrees Centigrade
by first converting from binary to decimal, dividing by 2, and then
subtracting 273d.
Temperature in °C = [(TK <9:0>)/2] - 273
(EQ. 4)
The practical range for the temp sensor register output is from 446d
to 726d, or -50°C to +90°C. The temperature compensation
24
FN6667.5
December 13, 2011