Question

1.  Assume that the Instruction Pointer, EIP, contains 175₁₀ and the assembly language representation of the instruction in memory at address 175₁₀ is JAE 136. If the flags are currently CF=0, ZF=0 and SF=0 what is the value of the EIP after the instruction executes?

2.

Assume that the instruction pointer, EIP, initially contains 49₁₀ and the assembly language representation of the instructions in memory starting at address 49₁₀ is

Instruction Address	Instruction
49	OR BL, 0x34
50	JE 79

Before the instruction sequence is executed, the flags are CF=1, ZF=0 and SF=1 and the Registers have the values AL=0x37, BL=0xEC CL=0xB8 and DL=0x99. What is the value of the instruction pointer after the sequence executes?

3. Assume that before the instruction is executed, the flags are CF=1, ZF=1 and SF=1 and the Registers have the values AL=0xAF, BL=0x75 CL=0x48 and DL=0xEA.

What are the values of the flags after the instruction ADD AL, 0xF4 executes?

CF =

ZF =

SF =

4.  Assume that the Instruction Pointer, EIP, contains 175₁₀ and the assembly language representation of the instruction in memory at address 175₁₀ is JAE 136. If the flags are currently CF=0, ZF=0 and SF=0 what is the value of the EIP after the instruction executes?

Answer 1

1.

EIP is the Instruction Pointer Register which speaks to the address of the instruction to be executed straightaway.

Right now, EIP = 175 10

The current flag values are CF = 0, ZF = 0 and SF = 0

where CF shows the carry Flag, ZF demonstrates the Zero Flag and SF indicates the Sign Flag.

The instruction to be executed is JAE 136

where JAE shows the Jump on Above or Equal to. This instruction performs the bounce if the carry flag is set to 0. for example assuming CF = 0, the hop is taken, else the hop won't be taken.

According to the status of the flags, CF = 0 and thus the jump is taken to the address 136. Since the following instruction to be executed is at address 136, EIP will be stacked with address 136.

Subsequently EIP = 136.

4.

EIP is the Instruction Pointer Register which speaks to the address of the instruction to be executed straightaway.

Right now, EIP = 175 10

The current flag values are CF = 0, ZF = 0 and SF = 0

where CF shows the carry Flag, ZF demonstrates the Zero Flag and SF indicates the Sign Flag.

The instruction to be executed is JAE 136

where JAE shows the Jump on Above or Equal to. This instruction performs the bounce if the carry flag is set to 0. for example assuming CF = 0, the hop is taken, else the hop won't be taken.

According to the status of the flags, CF = 0 and thus the jump is taken to the address 136. Since the following instruction to be executed is at address 136, EIP will be stacked with address 136.

Subsequently EIP = 136.