INTRODUCTION

GPIO expanders provide easy I/O expansion using standard serial interfaces. GPIO products are used to increase the I/O on an MCU or provide remote I/O using a serial interface.

This application note discusses the feature set and use of the MCP23X08/17 (8-bit and 16-bit) GPIO Expanders.

FEATURES

This application note discusses some of the features of the MCP23X08/17 and how they may be used in an application:

• I/O Port Description

• 8/16-Bit Mode (MCP23X17 only)

• Interrupt Features

- Mapping Interrupts

- Mirroring Interrupts (MCP23X17 only)

- Servicing Interrupts

• Internal Address Pointer Control

• Hardware Address Pin on SPI