PT7C4337 Datasheet, PDF (7/25 Pages) List of Unclassifed Manufacturers – Real-time Clock Module (I2C Bus)

Data Sheet
PT7C4337
Real-time Clock Module (I²C Bus)
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Control and status register
Addr.
Description
D7
D6
(hex)
0E
Control
/ETIME
0
(default)
0
0
0F
Status
(default)
OSF
0
1
0
D5
D4
D3
D2
D1
D0
0
RS2
RS1
INTCN A2IE
A1IE
0
1
1
0
0
0
0
0
0
0
A2F
A1F
0
0
0
0
Undefined Undefined
Oscillator related bits
• /ETIME
Enable oscillator and time count chain bit.
/ETIME
Data
Description
Read / Write
0 Enable oscillator and time count chain.
1 Disable oscillator and time count chain.
Default
• OSF
Oscillator Stop Flag.
A logic 1 in this bit indicates that the oscillator either is stopped or was stopped for some period of time and may be used to judge
the validity of the clock and calendar data. This bit is set to logic 1 anytime that the oscillator stops. The following are examples
of conditions that can cause the OSF bit to be set:
1) The first time power is applied.
2) The voltage present on VCC is insufficient to support oscillation.
3) The /ETIME bit is turned off.
4) External influences on the crystal (e.g., noise, leakage, etc.).
This bit remains at logic 1 until written to logic 0.
Square wave frequency selection bits
• RS2, RS1
Square wave Rate Select. These bits control the frequency of the square-wave output when the square wave has been enabled.
RS2, RS1
Data
SQW output freq. (Hz)
00 1
Read / Write
01 4.096k
10 8.192k
11 32.768k
Default
PT0205(02/07)
7
Ver: 1