m41st95w STMicroelectronics, m41st95w Datasheet - Page 20

• Manufacturer Part Number: m41st95w
• Description: 5.0 Or 3.0v, 512 Bit 64 Bit X 8 Serial Rtc Spi Sram And Nvram Supervisor
• Manufacturer: STMicroelectronics

M41ST95Y*, M41ST95W
Square Wave Output
The M41ST95Y/W offers the user a programma-
ble square wave function which is output on the
SQW pin. RS3-RS0 bits located in 13h establish
the square wave output frequency. These fre-
quencies are listed in Table 6. Once the selection
Table 6. Square Wave Output Frequency
Full-time F
(Available only in 28-pin, 300mil SOIC (MX) package).
The M41ST95Y/W offers the user a special 32kHz
square wave function which is always output on
the F
oscillator is running (ST Bit = '0'). This function is
available within four seconds of initial power-up
20/35
32k
RS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
pin (Pin 21) as long as V
32k
Square Wave Output
RS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Square Wave Bits
CC
V
SO
, and the
RS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
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.
and can only be disabled by setting the ST Bit to
'1,' or while the device is in back-up. If not used,
the F
to float.
RS0
32k
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
pin should be disconnected and allowed
Frequency
32.768
8.192
4.096
2.048
1.024
None
512
256
128
64
32
16
8
4
2
1
Square Wave
Units
kHz
kHz
kHz
kHz
kHz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
–