6.4. Event bus interface

The event bus, EVNTBUSm, is used to signal when an event has occurred. The event bus includes most, but not all, of the events that can be counted by the performance monitoring unit. Each individual event is assigned to an individual bit of this bus, and this bit is asserted for one cycle each time the event occurs.

The event bus only signals events when it is enabled. Set the X bit in the Performance Monitor Control Register to enable the event bus. See c9, Performance Monitor Control Register.

See Table 6.1 to see which bit of the event bus each event is signaled on.


If an event is being counted in the PMU, the count might not be incremented in exactly the same cycle that the event is signaled on the event bus.

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