概觀
The IS31IO7325 2-wire serial-interfaced peripheral
features 16 I/O ports. Ports are divided into eight push
pull I/Os and eight open-drain I/Os and transition
detection.
Any of the 16 I/O ports can be configured as an input
or an output. All I/O ports configured as inputs are
continuously monitored for state changes (transition
detection). State changes are indicated by the INTB
output. The interrupt is latched, allowing detection of
transient changes. When the IS31IO7325 is
subsequently read through the serial interface, any
pending interrupt is cleared.
The open-drain outputs are rated to sink 20mA at
0.22V headroom, and are capable of driving LEDs.
The RSTB input clears the serial interface, terminating
any I2C communication to or from the IS31IO7325. The
IS31IO7325 uses two address inputs to allow 4 I2C
slave addresses. The slave address also determines
the power-up logic state for the I/O ports.