TWO NUMBERS COMPARATOR IN VLSI CIRCUITS

摘要

A two numbers comparator of a semiconductor integrated circuit is provided to reduce the number of transistors, and compare the sizes of two numbers efficiently without using a subtracter. A two numbers comparator includes a superior encoding unit(10), a bitwise competition unit(20) and a determination unit(30). The superior encoding unit converts a bit of a number when the bit is superior to the corresponding bit of another number. The bitwise competition unit sequentially compares bits of two superior values output from the superior encoding unit from the most significant bits and determines the sizes of the bits. The determination unit receives the values from the bitwise competition unit and determines the sizes of the two numbers according to the first upper bits having the determined sizes.