Monitors, Monitors Everywhere – Who Is Monitoring the Monitors

In a verification environment the task of a monitor is to monitor activity on a set of DUT pins. This could be as simple as looking at READ/WRITE pins or as complex as a complete protocol bus, such as AXI or PCIe. In a very simple case a monitor can be looking at a pin or a set of pins and generating an event or raising a flag every time there is a change in signal values. The flag or event can trigger a scoreboard or coverage collector to perform an activity.