In the following problem sets, we will use this expanded set of opcodes for our hypothetical machine:

0001 = Load AC from memory (LOAD)

0010 = Store AC to memory (STORE)

0100 = Subtract memory from AC (result in AC) (SUB)

0101 = Add to AC from memory (result in AC) (ADD)

0110 = Jump to address, absolute jump (JMP)

0111 = Jump to address if result was 0, conditional jump (JMPZ)

1000 = Jump to address if result was negative, conditional jump (JMPN)

Problem 4 + Fetch stage Execute stage Memory CPU registers CPU registers 1941 0300 PC 300 300 301 Memory 1941 4941 PC | 4941 0000 AC 301 302 7301 IR 302 7301 IR 940 0004 940 OOFC 941 Fetch 1 941 Execute 1 CPU registers CPU registers Memory 1941 Memory 1941 300 PC 300 PC 301 4941 301 4941 AC AC TIR 302 7301 302 7301 IR 940 940 941 941 Fetch 2 Execute 2 CPU registers Memory CPU registers Memory 1941 300 PC 300 1941 301 4941 AC 301 4941 PC | AC IR 302 7301 IR 302 7301 940 940 941 941 Fetch 3 Execute 3 Memory CPU registers CPU registers PC PC 300 301 1941 4941 300 301 Memory 1941 4941 7301 | | 302 7301 IR 302 IR 940 940 941 941 Fetch 4 Execute 4