AN1043
Overview
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.
- 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. The MCP23X08 are 8-bit GPIO Expanders:
- MCP23008: I2C™ Interface
- MCP23S08: SPI Interface The MCP23X17 are 16-bit GPIO Expanders:
- MCP23017: I2C Interface
- MCP23S17: SPI Interface The functions and features of the MCP23X08 and MCP23X17 are basically the same, except where otherwise noted. …be configured as an input. The output driver is …be configured as an output. The output driver disabled (high impedance) 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 is enabled and the value in the latch is driven on the pin.
