The ET6416 is a 16-bit general purpose I/O expander that provides remote I/O expansion for most micro-controller families via the I2C-bus interface.
ET6416 provides a simple solution for I/O port expansion, which can be realized with little interconnection. In addition to providing a set of flexible GPIO ports, it also supports the level conversion between different voltage devices, so that it can be flexibly applied in multi voltage mixed signal environment.
ET6416 has two supply voltage port: VDDI and VDDP, VDDI provides the power supply voltage for the interface of the main control terminal(micro-controller) and VDDP provides the power supply voltage for the core circuit and Port P.
ET6416 has four pairs of 8-bits registers: configuration register, input register, output register and polarity reversal register.
When power-on, all I/O ports are configured to input status. By configuring the I/O ports’ configuration register, the system can determine the input and output status of each I/O port. Each input or output data is stored in the corresponding input or output register. The polarity of input registers can be flipped by configuring polarity reversal registers to save external logic gates.
When time-out or error operation occurs, the host can reset ET6416 by applying a low level on Port. When power on , all registers are in default state, and I2C BUS/SM BUS state machine is initialized.
When any input state is different from its corresponding input register state, the ET6416 open drain interrupt output is active to indicate to the host that the input state has changed.
The can be connected to the interrupt input of the micro-controller. By sending the interrupt signal, the microcontroller port is informed that there is data entering, instead of passing through I2C BUS.
The Port P output of ET6416 can provide 25mA perfusion current, which can directly drive LED.
The hardware address pin (ADDR) can be used to program and change the I2C BUS address.