Q10

The instruction format of a CPU is:

$\text{Mode}$ and $\text{RegR}$ together specify the operand. $\text{RegR}$ specifies a CPU register and $\text{Mode}$ specifies an addressing mode. In particular, $\text{Mode}=2$ specifies that ‘the register $\text{RegR}$ contains the address of the operand, after fetching the operand, the contents of $\text{RegR}$ are incremented by $1$'. An instruction at memory location $2000$ specifies $\text{Mode}= 2$ and the $\text{RegR}$ refers to program counter (PC).