M41T66Q6F STMicroelectronics, M41T66Q6F Datasheet - Page 18

• Manufacturer Part Number: M41T66Q6F
• Description: IC RTC SERIAL W/ALARM 16-QFN
• Manufacturer: STMicroelectronics
• Type: Clock/Calendar/Alarmr

Specifications of M41T66Q6F

• Memory Size: 16B
• Time Format: HH:MM:SS:hh (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.5 V ~ 4.4 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8377-2

Clock operation
3.3
Note:
18/33
Setting alarm clock registers
Address locations 0Ah-0Eh contain the alarm settings. The alarm can be configured to go
off at a prescribed time on a specific month, date, hour, minute, or second, or repeat every
year, month, day, hour, minute, or second. Bits RPT5–RPT1 put the alarm in the repeat
mode of operation.
default to the once per second mode to quickly alert the user of an incorrect alarm setting.
When the clock information matches the alarm clock settings based on the match criteria
defined by RPT5–RPT1, the AF (alarm flag) is set. If AFE (alarm flag enable) is also set, the
alarm condition activates the IRQ/OUT. To disable the alarm, write '0' to the alarm date
register and to RPT5–RPT1.
If the address pointer is allowed to increment to the flag register address, an alarm condition
will not cause the interrupt/flag to occur until the address pointer is moved to a different
address. It should also be noted that if the last address written is the “alarm seconds,” the
address pointer will increment to the flag address, causing this situation to occur.
The IRQ/OUT output is cleared by a READ to the flags register as shown in
subsequent READ of the flags register is necessary to see that the value of the alarm flag
has been reset to '0.'
Figure 13. Alarm interrupt reset waveform
Table 3.
RPT5
1
1
1
1
1
0
Alarm repeat modes
RPT4
1
1
1
1
0
0
Table 3
RPT3
shows the possible configurations. Codes not listed in the table
1
1
1
0
0
0
RPT2
1
1
0
0
0
0
RPT1
1
0
0
0
0
0
Once per second
Once per minute
Once per month
Alarm setting
Once per hour
Once per year
Once per day
Figure
M41T66
13. A