PT7C4337 Datasheet, PDF (8/25 Pages) List of Unclassifed Manufacturers – Real-time Clock Module (I2C Bus)

Data Sheet
PT7C4337
Real-time Clock Module (I²C Bus)
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Interrupt related bits
• INTCN
Interrupt Output pin select bit. This bit controls the relationship between the two alarms and the interrupt output pins.
INTCN Data
Description
Read /
Write
A match between the timekeeping registers and the alarm 1 registers activates the INTA pin (if the
1 alarm 1 is enabled) and a match between the timekeeping registers and the alarm 2 registers activates
the SQW/INTB pin (if the alarm 2 is enabled).
A match between the timekeeping registers and either alarm 1 or alarm 2 registers activates ^Default
0 the INTA pin (if the alarms are enabled). In this configuration, a square wave is output on
the SQW/INTB pin.
• A1IE
Alarm 1 Interrupt Enable.
A1IE
Data
Description
Read /
Write
0 The A1F bit does not initiate the INTA signal.
1 Permits the alarm 1 flag (A1F) bit in the status register to assert INTA.
Default
• A1F
Alarm 1 Flag.
A1F
Data
Read / Write 0
Read
1
Description
The time do not match the alarm 1 registers.
Default
Indicates that the time matched the alarm 1 registers. If the A1IE bit is also logic 1, the INTA pin goes
low. A1F is cleared when written to logic 0. Attempting to write to logic 1 leaves the value unchanged.
• A2IE
Alarm 2 Interrupt Enable.
A2IE
Data
Description
Read /
Write
0 The A2F bit does not initiate an interrupt signal.
Default
Permits the alarm 2 flag (A2F) bit in the status register to assert INTA (when INTCN = 0) or to assert
1
SQW/INTB (when INTCN = 1).
• A2F
Alarm 2 Flag.
A1F
Data
Read /
0
Write
Read
1
Description
The time do not match the alarm 2 registers.
Default
Indicates that the time matched the alarm 1 registers. This flag can be used to generate an interrupt on
either INTA or SQW/INTB depending on the status of the INTCN bit. If the INTCN = 0 and A2F = 1
(and A2IE = 1), the INTA pin goes low. If the INTCN = 1 and A2F = 1 (and A2IE = 1), the
SQW/INTB pin goes low. A2F is cleared when written to logic 0. Attempting to write to logic 1 leaves
the value unchanged.
PT0205(02/07)
8
Ver: 1