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

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ID 683386
Date 9/22/2014
Public
Document Table of Contents
Document Table of Contents x
1. Using Altera MAX Series as Microcontroller I/O Expanders
1. Using Altera MAX Series as Microcontroller I/O Expanders x
1.1. Advantages of Using Altera Devices as I/O Expanders 1.2. Microcontroller I/O Expander Implementation 1.3. Microcontroller I/O Expander Configuration 1.4. Resource Usage in Microcontroller I/O Expander Target Devices 1.5. Microcontroller I/O Expander Design Verification 1.6. Microcontroller I/O Expander Application 1.7. Document Revision History
1.2. Microcontroller I/O Expander Implementation x
1.2.1. Pin Functions in the Microcontroller I/O Expander 1.2.2. Functional Description of the Microcontroller I/O Expander
1.5. Microcontroller I/O Expander Design Verification x
1.5.1. Simulating Microcontroller I/O Expander Write Mode Timing 1.5.2. Simulating Microcontroller I/O Expander Read Mode Timing
1. Using Altera MAX Series as Microcontroller I/O Expanders

1.5.1. Simulating Microcontroller I/O Expander Write Mode Timing

Figure 2. Write Mode Timing Simulation of the Microcontroller I/O Expander


  1. With all the I/O pins in tri-state mode, initialize each port.
  2. After initialization, configure port A and port B as output, and port C and port D as input.
  3. Enable port B for write operation.
    When WR asserts a low signal, the clock through the output data registers is enabled and creates a new output value (146) at the output port B from the MCU port.
  4. Once the LOAD signal asserts low, enable port A.
    When the WR signal is low to enable the clock through the output data registers, the MCU port data (108) is created at the output port A.
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