4.3.3 Reading MSI Count Values

In the demo, Root Port can read the MSI count values for push-button interrupts on the Endpoint board.

To read the MSI count values:

  1. Click Enable Interrupt Session button, as shown in the following figure.
    Figure 4-9. Enable Interrupt Session Option

    When the Interrupt session is enabled, the GUI sends the Enable Interrupt session request to the RISC-V processor. PF_PCIE_0 receives the number of MSI requested by the Endpoint. The following table lists the four types of MSI allocated by Root port in the reference design.

    Table 4-1. Allocated MSIs
    MSI NumberInterrupt Type on the Endpoint BoardMapped Interrupt Counter on the GUI
    1SW10Interrupt Counter1
    2SW9Interrupt Counter2
    3SW8Interrupt Counter3
    4SW7Interrupt Counter4
  2. Press switch and observe interrupt count.
    Figure 4-10. Interrupt Counter4
  3. Click Clear Interrupt Count button to clear all of the Interrupt counters on the GUI.