EFFECTIVE DIGIT COUNT ON OPERAND

摘要

In a microprogrammed data processing system, the throughput of the system is increased by apparatus which counts the number of effective digits in an operand which is the result of a decimal numeric instruction being processed by the system. The apparatus receives operand words the operand's least significant word first, in response to a predetermined microword. The apparatus includes a first register which stores a count of one less than the number of words received; an adder which increments the output of the first register if the word received has a decimal zero in the high order position of the word; and a second register which stores the output of the adder in a word count portion and the number of leading zeros in a digit count portion of the second register. The second register is loaded on the same cycle the word is processed providing the word does not contain all decimal zeros.