Chapter 2, Problem 21CRP

Explanation of Solution

Determine the condition of machine with its program counter containing $0\times \text{AF}$:

The address content of the program is shown as follows:

$\begin{array}{l}\text{AF}\text{B0}\\ \text{B0}\text{B0}\\ \text{B1}\text{AF}\end{array}$

The program counter instruction register is as follows:

$\begin{array}{l}\text{AF}\text{B0B0}\\ \text{B0}\text{B0AF}\\ \text{AF}\text{B0B0}\\ \text{B0}\text{B0AF}\end{array}$

$\begin{array}{l}\mathrm{..}\\ \mathrm{..}\\ \mathrm{..}\end{array}$

Explanation:

• The address $\text{B0}$ is placed in the program counter because of the execution of first instruction which will cause the address $\text{B0}$ to be assigned as a program counter