The MM54C85 MM74C85 is a four-bit magnitude comparator which will perform comparison of straight binary or BCD codes The circuit consists of eight comparing inputs (A0 A1 A2 A3 B0 B1 B2 B3) three cascading inputs (A l B A k B and A e B) and three outputs (A l B A k B and A e B) This device compares two four-bit words (A and B) and determines whether they are ``greater than '' ``less than '' or ``equal to'' each other by a high level on the appropriate output For words greater than four-bits units can be cascaded by connecting the outputs (A l B A k B and A e B) of the least significant stage to the cascade inputs (A l B A k B and A e B) of the next-significant stage In addition the least significant stage must have a high level voltage (VIN(1)) applied to the A e B input and low level voltage (VIN(0)) applied to A l B and A k B inputs