M41T83SQA6F STMicroelectronics, M41T83SQA6F Datasheet - Page 40

• Manufacturer Part Number: M41T83SQA6F
• Description: IC RTC SERIAL W/BATT SW 16QFN
• Manufacturer: STMicroelectronics
• Type: Clock/Calendar/Alarmr

Specifications of M41T83SQA6F

• Memory Size: 32B
• Time Format: HH:MM:SS:hh (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Clock Format: 12Hr / 24Hr
• Clock Ic Type: RTC
• Interface Type: I2C, Serial
• Supply Voltage Range: 3V To 5.5V
• Digital Ic Case Style: QFN
• No. Of Pins: 16
• Rohs Compliant: Yes
• For Use With: 497-10833 - DAUGHTER-CARD M41T83SQA6E QFN16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6887-2; M41T83SQA6F

Clock operation
3.11
3.12
Note:
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The M41T8x only checks the battery when powered by V
while in backup mode. Thus, users are advised that during long periods in backup mode,
the battery can drop to a level at which timekeeping may fail or data becomes corrupted. If,
at power-up, a battery low is indicated, data integrity should be verified.
Forcing a battery check
If it is desired to check the battery at an arbitrary time, one common technique is for the
application software to write the time to just before midnight, 23:59:59, and then wait two
seconds thereby letting the clock rollover and causing the BL bit to update. The application
then restores the time back to its previous value plus two seconds.
Century bits
These two bits will increment in a binary fashion at the turn of the century, and handle all
leap years correctly. See
Table 14.
1. Leap year occurs every four years (for years evenly divisible by four), except for years evenly divisible by
Oscillator fail detection
If the oscillator fail (OF) bit is internally set to a '1,' this indicates that the oscillator has either
stopped, or was stopped for some period of time. This bit can be used to judge the validity of
the clock and date data. This bit will be set to '1' any time the oscillator stops.
In the event the OF bit is found to be set to '1' at any time other than the initial power-up, the
STOP bit (ST) should be written to a '1,' then immediately reset to 0. This will restart the
oscillator. The following conditions can cause the OF bit to be set:
●
If the OF bit cannot be written to '0' four seconds after the initial power-up, the STOP bit (ST)
should be written to a '1,' then immediately reset to 0.
●
●
●
For the M41T83, if the oscillator fail interrupt enable bit (OFIE) is set to a '1,' the
IRQ1/FT/OUT pin will also be asserted (see
conditions which apply). The IRQ1/FT/OUT output is de-asserted by resetting the OF bit to
0, NOT by reading the flags register. The OF bit will remain a '1' until written to 0. Reading
the flags register has no effect on OF.
100. The only exceptions are those years evenly divisible by 400 (the year 2000 was a leap year, year
2100 is not).
The first time power is applied (defaults to a '1' on power-up).
The voltage present on V
The ST bit is set to '1.'
External interference of the crystal
CB0
0
0
1
1
Century bits examples
Table 14
Doc ID 12578 Rev 12
CC
CB1
or battery is insufficient to support oscillation.
0
1
0
1
for additional explanation.
Section 3.13
Leap Year?
Yes
No
No
No
CC
and
. It does not check the battery
Section 3.14
M41T82-M41T83
Example
for additional
2000
2100
2200
2300
(1)