PCA9675BS NXP [NXP Semiconductors], PCA9675BS Datasheet - Page 16

• Manufacturer Part Number: PCA9675BS
• Description: Remote 16-bit I/O expander for Fm+ I2C-bus with interrupt
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCA9675_1
Product data sheet
8.4 Power-on reset
8.5 Interrupt output (INT)
When power is applied to V
a reset condition until V
and the PCA9675 registers and I
states. Thereafter V
The PCA9675 provides an open-drain interrupt (INT) which can be fed to a corresponding
input of the microcontroller (see
chips a kind of master function which can initiate an action elsewhere in the system.
An interrupt is generated by any rising or falling edge of the port inputs. After time t
signal INT is valid.
The interrupt disappears when data on the port is changed to the original setting or data is
read from or written to the device which has generated the interrupt.
In the write mode, the interrupt may become deactivated (HIGH) on the rising edge of the
write to port pulse. On the falling edge of the write to port pulse the interrupt is definitely
deactivated (HIGH).
The interrupt is reset in the read mode on the rising edge of the read from port pulse.
During the resetting of the interrupt itself, any changes on the I/Os may not generate an
interrupt. After the interrupt is reset any change in I/Os will be detected and transmitted as
an INT.
Fig 19. Application of multiple PCA9675s with interrupt
MICROCOMPUTER
DD
INT
Rev. 01 — 1 February 2007
must be lowered below 0.2 V to reset the device.
DD
has reached V
Remote 16-bit I/O expander for Fm+ I
DD
V
DD
, an internal Power-On Reset (POR) holds the PCA9675 in
Figure
2
C-bus/SMBus state machine will initialize to their default
PCA9675
device 1
INT
17,
POR
Figure
. At that point, the reset condition is released
PCA9675
device 2
18, and
INT
Figure
19). This gives these
2
C-bus with interrupt
PCA9675
© NXP B.V. 2007. All rights reserved.
PCA9675
device 8
002aab635
INT
(v)D
16 of 34
the