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 Expand-
ers.
The MCP23X08 are 8-bit GPIO Expanders:
• MCP23008: I
2
C™ Interface
• MCP23S08: SPI Interface
The MCP23X17 are 16-bit GPIO Expanders:
• MCP23017: I
2
C Interface
• MCP23S17: SPI Interface
The functions and features of the MCP23X08 and
MCP23X17 are basically the same, except where
otherwise noted. AN1043
Unique Features of the MCP23X08/17 GPIO Expanders
Author: Pat Richards I/O PORT DESCRIPTION
Microchip Technology Inc. The I/O port is highly configurable for maximum
flexibility. Figure 1 is a simplified block diagram of an
INTRODUCTION I/O port pin. The port can either drive logic levels on the
pin, or read logic levels from the pad. The level on the
GPIO expanders provide easy I/O expansion using pad can be read at any time, regardless if the pin is
standard ser……
