hardwarecountermålinger

A hardware counter is a digital circuit that records the number of times a specific event occurs or a clock signal advances. It is typically implemented as a group of flip-flops forming a register that increments its value on a trigger, such as a clock edge or an input pulse. Hardware counters are fundamental building blocks in timing, measurement, and control circuits.

Counters come in various forms. Binary counters increment in binary and can be designed as up counters that only increase, or as up/down counters that can both increment and decrement. BCD (binary coded decimal) counters increase in decimal digits for easier display or interfacing with decimal displays. Modulo-n counters reset after reaching a predetermined value, providing a fixed counting cycle. More specialized variants include Gray-code counters, which change only one bit per count to minimize switching activity, and ring or Johnson counters used in sequenced output designs.

Architectures are broadly categorized as ripple (asynchronous) counters, where each flip-flop’s output feeds the next, and synchronous counters, where all flip-flops share a common clock for faster and more predictable operation. Counters may include features such as preset or load inputs to initialize to a specific value, enable inputs to gate counting, and clear inputs to reset to zero. Decoding logic is often used to drive displays or to generate control signals when the counter reaches a certain value.

Common applications include dividing a clock signal to obtain lower frequencies, counting events for measurement and timing, driving digital displays, and serving as timing references in microcontrollers and embedded systems. In computing hardware, hardware performance counters track events like instructions executed or cycles elapsed for profiling and optimization.