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

1.5.2. Simulating Microcontroller I/O Expander Read Mode Timing

Figure 3. Read 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 ports A, B, C, D as input.
  3. Enable port C for read operation.
    When RD asserts a low signal, the clock through the input data registers is enabled and creates a new output value (214) at the MCU port from port C.
  4. Once the LOAD signal asserts low, enable port D.
    When the RD signal is low to enable the clock through the input data registers, port D data (146) is created at the MCU port.
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