Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

3.6.5.5.7. Add the PIO

PIO signals provide an easy method for Nios® II processor systems to receive input stimuli and drive output signals. Complex control applications might use hundreds of PIO signals which the Nios® II processor can monitor. This design example uses eight PIO signals to drive LEDs on the board. To add the PIO, perform the following steps:

Note: Perform these steps even if your target board does not have LEDs.
  1. On the IP Catalog tab, expand Processors and Peripherals, expand Peripherals, and then click PIO .
  2. Click Add.
    The PIO (Parallel I/O) parameter editor appears and do not change the default settings.
  3. Click Finish and return to the Platform Designer System Contents tab.
    The PIO instance appears in the system contents table.
  4. In the Name column, right-click the PIO and click Rename.
  5. Type led_pio and press Enter.
  6. Connect the clk port of the clk_0 clock source to the clk port of the PIO.
  7. Connect the clk_reset port of the clk_0 clock source to the reset port of the PIO.
  8. Connect the data_master port of the Nios® II processor to the s1 port of the PIO.
  9. In the external_connection row, click Click to export in the Export column to export the PIO ports.