M41T62 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'M41T62' PDF : 41 Pages View PDF
Clock operation
M41T62/63/64/65
3.6
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 Table 8. Once the selection of the SQW frequency has been
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 32 KHz
(except for M41T64, which defaults disabled).
Table 8.
Square wave output frequency
Square wave bits
RS3
RS2
RS1
RS0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
Square wave
Frequency
None
32.768
8.192
4.096
2.048
1.024
512
256
128
64
32
16
8
4
2
1
Units
–
kHz
kHz
kHz
kHz
kHz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
3.7
Full-time 32 KHz square wave output (M41T64)
The M41T64 offers the user a special 32 KHz square wave function which is enabled on
power-up to output on the F32K pin as long as VCC ≥ 1.3 V, and the oscillator is running
(ST 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 F32K pin
should be disconnected and allowed to float.
28/41
Doc ID 10397 Rev 14
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