AN 265: Using Altera MAX Series as Microcontroller I/O Expanders

ID 683386
Date 9/22/2014
Public

1.2. Microcontroller I/O Expander Implementation

The I/O expander in this design example includes four ports—A, B, C, and D:

  • You can program each port independently as I/O ports.
  • Each port is 8 bits wide.
  • Each port is bidirectional and acts as input port if tri-stated.
  • To perform read and write operations, connect any of these ports with the microcontroller unit (MCU) port.
Figure 1. Block Diagram of Microcontroller I/O Expander Design Example