ISL12022MIBZ-T Intersil, ISL12022MIBZ-T Datasheet - Page 28

• Manufacturer Part Number: ISL12022MIBZ-T
• Description: IC RTC/CALENDAR TEMP SENS 20SOIC
• Manufacturer: Intersil
• Type: Clock/Calendarr

Specifications of ISL12022MIBZ-T

• Memory Size: 128B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ISL12022MIBZ-TCT

Daylight Savings Time (DST) Example
DST involves setting the forward and back times and
allowing the RTC device to automatically advance the
time or set the time back. This can be done for current
year, and future years. Many regions have DST rules that
use standard months, weeks and time of the day, which
permit a pre-programmed, permanent setting.
Table 26 shows an example setup for the ISL12022M.
Month Forward and
DST Enable
Week and Day Forward
and select Day/Week,
not Date
Date Forward
Hour Forward
Month Reverse
Week and Day Reverse
and select Day/Week,
not Date
Date Reverse
Hour Reverse
VARIABLE
TABLE 26. DST EXAMPLE
April
1st Week and
Sunday
not used
2am
October
Last Week
and Sunday
not used
2am
VALUE
28
15h
16h
17h
18h
19h
1Ah
1Bh
1Ch
REGISTER
84h
48h
00h
02h
10h
78h
00h
02h
VALUE
ISL12022M
The Enable bit (DSTE) is in the Month forward register,
so the BCD value for that register is altered with the
additional bit. The Week and Day values along with
Week/Day vs Date select bit is in the Week/Day register,
so that value is also not straight BCD. Hour and Month
are normal BCD, but the Hour doesn’t use the MIL bit
since Military time PM values are already discretely
different from AM/PM time PM values. The DST reverse
setting utilizes the option to select the last week of the
month for October, which could have 4 or 5 weeks but
needs to have the time change on the last Sunday.
Note that the DSTADJ bit in the status register monitors
whether the DST forward adjustment has happened.
When it is “1”, DST forward has taken place. When it is
“0”, then either DST reverse has happened, or it has
been reset either by initial power-up or if the DSTE bit
has been set to “0”.
June 4, 2010
FN6668.7