Event-driven processing

Event-driven (or event-based) processing means the hardware computes and communicates only when something changes — a detected spike, a level crossing, a threshold event — rather than on every tick of a global clock. Idle circuitry consumes little or no dynamic power, so total energy scales with activity rather than with time. For neural data, which are sparse and bursty, this maps naturally: quiet periods cost almost nothing, and the system reacts with low latency when activity arrives.

The benefit is real only when average activity is low and the per-event overhead (arbitration, routing, wake-up) is small relative to the useful work. Under dense or high-rate activity, or with heavy overhead, an event-driven design can lose to a well-optimised clocked one.