74HC85N,
The 74HC85; 74HCT85 is a 4-bit magnitude comparator that can be expanded to almost any length. They perform comparison of two 4-bit binary, BCD or other monotonic codes and present the three possible magnitude results at the outputs,
where A3 and B3 are the most significant bits. For proper compare operation the expander inputs (IA>B, IA=B and IA<B) to the least significant position must be connected as follows: IA<B = IA>B = LOW and IA=B = HIGH. For words greater than 4-bits, units can be cascaded by connecting outputs QA>B, QA=B and QA<B to the corresponding inputs of the significant comparator. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.
