Design an equivalence checker for 4-bit binary numbers. The equivalence checker sequentially receives two binary numbers A and B as the input (LSB first) and determines if they are equal. As soon as the result is certain, the equality checker sets its output C (certain) to 1. If the result is uncertain, C = 0. In addition, the output E=1 if the result is certain and the numbers are equal, whereas E=0 if the result is certain and the numbers are different. If the result is uncertain, the value of E is not relevant. After comparing two 4 bit numbers, the process is repeated.

comp: one 4-bit shift-register that is initialized as 0001, two bidirectional 4-bit shift-registers (without asynchronous clear), one 4-bit magnitude comparator as in the lecture, one three-input OR gate.