Remote 4-Bit I²C and SMBus I/O expander with configuration register and interrupt

The TCA9536 is a 4-bit I/O expander for the I2C

bus and is designed for 1.65-V to 5.5-V VCC operation. It provides

general-purpose remote I/O expansion for most microcontroller families via the

I2C interface.

The system controller can enable the I/Os as either inputs or outputs by writing to the I/O

configuration register bits. The data for each input or output is kept in the corresponding

input or output register. The polarity of the Input Port register can be inverted with the

Polarity Inversion register. There is an additional

special function register that can be used to disable the internal pull-up resistors and

P3 override to an INT output.

The TCA9536

open-drain interrupt output ( when P3 is

configured as INT in the special

function register) is activated when any

input differs from its corresponding Input Port

register state and is used to indicate to the

system controller that an input state has

changed.

The system processor can reset the TCA9536 in the event of a timeout or other improper operation by

using an I2C soft reset command, which puts the registers in their default

state.

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