Experiment 2 programming with machine instructions and assembly instructions

Experiment conclusion

Lab task (1)

1. Use the e command to modify ~ 0021: F data, and the correct write operations after modification

2. Run Command A to enter the command

3. Single-step debugging of each line of commands

4. Memory values of each register after instruction execution

MoV ax, [0]; AX = 3130 H

Add ax, [2]; AX = 6462 H

MoV BX [4]; BX = 3534 H

Add Bx, [6]; BX = 6c6ah

Push ax; SP = 00feh; the address of the modified memory unit is 2200: Fe and the content is 3130 H.

Push BX; SP = 00fch; the address of the modified memory unit is 2200: fc and the content is 6462 H.

Pop ax; SP = 00feh; AX = 6c6ah

Pop BX; SP = 0100 h; BX = 6462 H

Push [4]; SP = 00feh; the address of the modified memory unit is 2200: Fe, and the content is 3534 H.

Push [6]; SP = 00fch; the address of the modified memory unit is 2200: fc, And the content is 6c6ah

5. After "mov SS, ax" is executed, "mov ax, [0]" is directly executed, and "mov sp, 0100" is skipped ".

Cause: When the debug t command executes the command to modify the SS register, the next command is also executed.

 

Lab task (2)

1. Run Command A to enter the 7-line command and Run Command e to modify the value from ~ 2000: F value, view the modified part

MoV ax, 2000; Save the number H to the Register ax

MoV SS, ax; Save the number 2000h in the register ax to the stack segment register SS

MoV sp, 10; Save the number 10 h to the stack address register sp

The initial stack top is, and the initial stack bottom is.

2. debug each line of Assembly commands in one step. After each command is debugged in one step, run the D command to view ~ 2000: F value

After "mov SS, ax" is executed, the value of memory from to 2000: F changes to the last nine, and then every time a command is executed, the memory is from to 2000: the value variation in F is increased by one.

 

Summary and experiences

Through this experiment, I have basically understood the principles and basic operations of the stack. At the same time, I also found that when the debug t command executes the instruction to modify the SS register, the next instruction is also executed.

 

Experiment 2 programming with machine instructions and assembly instructions