DESCRIPTION

The HEF4585B is a 4-bit magnitude comparator which compares two 4-bit words (A and B), whether they are ‘less than’, ‘equal to’, or ‘greater than’. Each word has four parallel inputs (A0 to A3 and B0 to B3); A3 and B3 being the most significant inputs. Three outputs are provided; A greater than B (OA > B), A less than B (OA B, IA

For proper compare operation the expander inputs to the least significant position must be connected as follows: IA = B = IA > B = HIGH, IA B is connected to a HIGH).

Operation is not restricted to binary codes, the devices will work with any monotonic code. The function table describes the operation of the device under all possible logic conditions.