Q12

Assume that a CPU has only two registers $R_1$ and $R_2$ and that only the following instruction is available $XOR \: R_i, R_j;\{R_j \leftarrow R_i \oplus R_j, \text{ for } i, j =1, 2\}$ Using this XOR instruction, find an instruction sequence in order to exchange the contents of the registers $R_1$ and $R_2$

The line p of the circuit shown in figure has stuck at $1$ fault. Determine an input test to detect the fault.