HardwareTimer

HardwareTimer is a peripheral found in many microprocessors, microcontrollers, and system-on-chip devices that provides a programmable counter driven by a clock source. It is used to measure time intervals, generate periodic events, and drive other peripherals with precise timing. Unlike software timers implemented in an operating system, a hardware timer executes timing logic in dedicated hardware, offering higher accuracy and lower CPU overhead.

A typical hardware timer includes a counter register, one or more comparator or compare registers, and a prescaler to divide the input clock. It may also provide an auto-reload or period register to reset the counter automatically, producing regular interrupts or events. Some timers support input capture to record the time of external events, output compare to generate square waves or PWM signals, and one-shot modes for single timed actions. Interrupts are commonly used to notify the CPU when a match or overflow occurs, enabling precise scheduling or timekeeping.

Common timer types include general-purpose timers, interval timers, watchdog timers, and high-resolution timers. General-purpose timers are used for event timing and PWM, interval timers for periodic tasks, watchdogs for fault detection, and high-resolution timers for fine-grained timing in real-time systems. Applications span timekeeping, scheduling tasks, motor control, PWM generation, communication timeouts, and debouncing.

Design considerations include clock accuracy, jitter, interrupt latency, resource sharing with other peripherals, and power consumption. Hardware timers complement software timers by offloading precise timing to hardware, while software timers can coordinate broader scheduling and logic.