M41T62_06 STMICROELECTRONICS [STMicroelectronics], M41T62_06 Datasheet - Page 27

• Manufacturer Part Number: M41T62_06
• Description: Serial Access Real-Time Clock with Alarms
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M41T62/63/64/65
3.6
3.7
Square wave output (M41T62/63/64)
The M41T62/63/64 offers the user a programmable square wave function which is output on
the SQW pin. RS3-RS0 bits located in 04h establish the square wave output frequency.
These frequencies are listed in
completed, the SQW pin can be turned on and off under software control with the Square
Wave Enable Bit (SQWE) located in Register 0Ah.
The SQW output is an N-channel, open drain output driver for the M41T64, and a full CMOS
output driver for the M41T62/63. The initial power-up default for the SQW output is 32KHz
(except for M41T64, which defaults disabled).
Table 8.
Full-time 32KHz square wave output (M41T64)
The M41T64 offers the user a special 32KHz square wave function which is enabled on
power-up to output on the F
Bit = '0'). This function is available within one second (typ) of initial power-up and can only
be disabled by setting the 32KE Bit to '0' or the ST Bit to '1.' If not used, the F
be disconnected and allowed to float.
RS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Square wave output frequency
RS2
Square wave bits
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
32K
Table
pin as long as V
RS1
8. Once the selection of the SQW frequency has been
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
CC
RS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1.3V, and the oscillator is running (ST
Frequency
32.768
8.192
4.096
2.048
1.024
None
512
256
128
64
32
16
8
4
2
1
Square wave
Clock operation
32K
pin should
Units
kHz
kHz
kHz
kHz
kHz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
–
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