# counter

views updated May 23 2018

# counter

views updated Jun 27 2018

counter A clocked digital electronic device whose output takes up one and one only of a number, n, of distinct states upon the application of each clock pulse (see clock). The output thus reflects the total number of clock pulses received by the counter up to its maximum capacity, n. All n states are displayed sequentially for n active transitions of the clock, the sequence then repeating. Since n clock pulses are required to drive the output between any two identical states, counters provide a “divide-by-n action” and are thus also known as dividers.

A counter whose output is capable of displaying n discrete states before producing an overflow condition can also be called a mod-n counter (or modulo-n counter), since it may be considered to be counting input pulses to a base of n. The value of n is often an integer power of 2. Counters are generally formed by a cascaded series of clocked flip-flops (see cascadable counter), each of which provides a divide-by-two action. For a counter consisting of m flip-flops, the maximum capacity of the counter will be 2m since 2m discrete output states are possible, i.e. n is equal to 2m. These are known as binary counters.

Count lengths of other than integer multiples of two are possible. For example, a decade counter (or mod-10 counter) exhibits 10 separate and distinct states. To achieve this digitally requires a counter having at least four individual flip-flop elements, giving 24 or 16 possible output states; six of these states are prevented from occurring by a suitable arrangement of logic gates around the individual flip-flops. In multimode counters the number, n, of distinct states can be selected by the user.

# counter

views updated Jun 08 2018

counter 4 go counter to, oppose XIV; give a counterblow XIX. orig. aphetic of †acounter, var. of ENCOUNTER; in later use a fresh formation on COUNTER- or COUNTER 5.

# counter

views updated May 21 2018

counter 2
A. †opposite direction to that taken by the game XVI;

B. part of a horse's breast lying between the shoulders; curved part of a ship's stern XVII. f. COUNTER 3 or COUNTER 5.

# counter

views updated May 17 2018

counter 1 object used in counting; desk for counting money, etc., (hence) money-changer's table, tradesman's table in his shop. XIV. — AN. count(e)our, OF. conteo(i)r (mod. comptoir) :- medL. computātōrium, f. L. computāre COMPUTE.

# counter

views updated May 23 2018

counter 5 in the opposite direction. XV. — OF. countre :- L. contrā adv. and prep. against, in return; cf. CONTRA.

# counter

views updated Jun 11 2018

counter 3 opposed, opposite. XVI. adj. use of the prefix COUNTER-.

# counter

views updated May 23 2018

counter. Opposite, or against, hence used as a noun for a long narrow flat-topped construction to separate staff from customers in a bank, inn, or shop.