In addition to reading values from the VIO input probes, you can also monitor the activity of the VIO input probes. The activity detectors are used to indicate when the values on the VIO inputs have changed in between periodic updates to the Vivado IDE.
The VIO input probe activity values are shown as arrows in the activity column of the VIO Probes window of the VIO Dashboard window:
- An up arrow indicates that the input probe value has transitioned from a 0 to a 1 during the activity persistence interval.
- A down arrow indicates that the input probe value has transitioned from a 1 to a 0 during the activity persistence interval.
- A double-sided arrow indicates that the input probe value has transitioned from a 1 to a 0 and from a 0 to a 1 at least once during the activity persistence interval.
The persistence of how long the input activity status is displayed can be controlled by right-clicking a VIO input probe in the VIO Probes window of the VIO Dashboard window and selecting:
- Activity Persistence > Infinite to accumulate and retain the activity value until you reset it.
- Activity Persistence > Long (80 samples) to accumulate and retain the activity for a longer period of time.
- Activity Persistence > Short (8 samples) to accumulate and retain the activity for a shorter period of time.
You can also set the activity persistence using a Tcl command. For instance, to change the activity persistence on the VIO input probe called BUTTON_IBUF to a long interval, run the following Tcl command:
set_property ACTIVITY_PERSISTENCE LONG [get_hw_probes BUTTON_IBUF]The activity for all input probes for a given core can be reset by right-clicking the VIO core in the Hardware window and selecting Reset All Input Activity. You can also do this by running the following Tcl command:
reset_hw_vio_activity [get_hw_vios {hw_vio_1}]