CAT9534 Datasheet, PDF (7/16 Pages) ON Semiconductor – 8-bit I²C and SMBus I/O Port with Interrupt

¯IN¯T¯: Interrupt Output
The open-drain interrupt output is activated when one
of the port pins configured as an input changes state
(differs from the corresponding input port register bit
state). The interrupt is deactivated when the input
CAT9534
returns to its previous state or the input port register is
read. Changing an I/O from an output to an input may
cause a false interrupt if the state of the pin does not
match the contents of the input port register.
Data from
Shift Register
Data from
Shift Register
Write
Configuration Pulse
Configuration
Register
D
Q
FF
CK
Q
Write Pulse
D
Q
FF
CK
Q
Output Port
Register
Read Pulse
Q1
Q2
Input Port
Register
D
Q
LATCH
CK
Q
Output Port
Register Data
VCC
I/O₀ to I/O₇
VSS
Input Port
Register Data
To INT
Data from
Shift Register
Write
Polarity
Register
D
Q
FF
CK
Q
Polarity
Inversion Register
Polarity
Register Data
Figure 4. Simplified Schematic of I/O₀ to I/O₇
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7
Characteristics subject to change without notice
Doc. No. MD-9004 Rev. D