COUNTERS

• A counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal.
• Counters are used in digital electronics for counting purposes, they can count specific events happening in the circuit.
• In an UP counter, a counter increases count for every rising edge of clock.
• Counters can follow a certain sequence based on design, such as any random sequence 0,1,3,2….
• Counters can also be designed with the help of flip flops.
• Counters are used as frequency dividers where the frequency of given pulse waveform is divided.
• Counters are sequential circuits that count the number of pulses, which can be either in binary code or BCD form.
• The main properties of a counter are timing, sequencing, and counting.
• Counters work in two modes: Up counter and Down counter.
• Counters are broadly divided into two categories: Asynchronous counter and Synchronous counter.
• In an asynchronous counter, the first flip flop is driven by the main clock, and the clock input of the rest of the following flip flops is driven by the output of the previous flip flops.
• Asynchronous counters are also called Ripple counters as they are cascaded arrangements of flip flops where the output of one flip flop drives the clock input of the following flip flop.
• In a synchronous counter, each flip flop has one global clock which drives each flip flop, so output changes in parallel.
• The advantage of a synchronous counter over an asynchronous counter is that it can operate on higher frequency as it does not have cumulative delay because of same clock is given to each flip flop.