EECE $3435$ Lab $08$: Arithmetic$-$ Addition, Subtraction, Multiplication, Division Instructions

EECE $3435$ Lab $08$: Arithmetic$-$ Addition, Subtraction, Multiplication, Division Instructions

A$.$ Objectives: to understand and experiment on the arithmetic instructions

B$.$ Resources

Online resources

Textbook

C$.$ Lab Preparation

Use online resources or the textbook to understand the debug commands and assembly instructions used in the assignment.

Start the Debug Application.

First fill the memory with some data by executing the following command:

$-$f $0$ ffff DD $3$C C$1$ D$8$ B$6$ B$26$A F$1$ AA

Note that in the lab report, you will be required to show the results you obtained in your experiments. You thus need to take screenshots of your work.

D$.$ The Lab

Initialization of memory locations:

$1\mathrm{.}1$ Initialize segment registers and memory:

Use R command: DS $=0$B$50$ and CS $=0$A$50$

Note: this is to make the DS and CS occupy different space in memory.

Use f command: f DS:$0$ ffff DD $3$C C$1$ D$8$ B$6$ B$26$A F$1$ AA

$1\mathrm{.}2$: Reinitialize some memory locations:

$DS$: $100H=10H$;$DS$:$101=01H$;

$DS$:$120H=FFH$; $DS$: $121H=FFH$;

$DS$: $130H=08H$; $DS$: $131H=01H$;

$DS$: $150H=02H$; $DS$: $151H=01H$;

$DS$:$200H=30H$; $DS$: $201H=01H$;

$DS$:$210H=40H$; $DS$: $211=01H$; and

$DS$:$220H=30H$; $DS$:$221H=01H.$

$1\mathrm{.}3.$ Verify that the memory locations have been loaded with the correct data with the D command.

$2.$ Initialize registers:

$Ax=0020H$;

$Bx=0030H$;

$CX=0040H$;

$Dx=0050H$;

$SI=0100H$;

$DI=0200H$; and

$CF=1.$

Verify the register contents.

$3.$ Assemble the following instruction sequence into the memory starting at address CS$$

a$.$ ADD AX$,00$FF

b$.$ ADC SI$,$ AX

c$.$ INC BYTE PTR $[0100]$

d$.$ SUB DL$,$ BL

e$.$ SBB DL$,[0200]$

f$.$ DEC BYTE PTR $[$DI$+$BX$]$

g$.$ NEG BYTE PTR $[$DI$+0010]$

h$.$ MUL DX

i$.$ IMUL WORD PTR $[$BX$+$SI$]$

j$.$ DIV WORD PTR $[$SI$+0030]$

k$.$ IDIV WORD PTR $[$BX$][$SI$+0030]$

Verify these instructions are in the memory.

How many bytes of memory do the instructions take up$?$

Note: For instructions j and k$,$ you may encounter an interrupt$/$exception$.$ Try to find the reason behind it$,$ and modify the contents of registers with new values to avoid the divide overflow.

$4.$ Display the current state of the flags.

$5.$ Execute the instructions one at a time with the TRACE command. Describe the operation performed by each instruction. For each instruction, show where the source and destination operands are located, what results are produced, where are the results stored; and name the flags that changed in the given operation.

a$.$ Instruction$-$a

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

b$.$ Instruction$-$b

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

c$.$ Instruction$-$c

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

d$.$ Instruction$-$d

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

e$.$ Instruction$-$e

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

f$.$ Instruction$-$f

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

g$.$ Instruction$-$g

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

h$.$ Instruction$-$h

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

i$.$ Instruction$-$i

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

j$.$ Instruction$-$j

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

k$.$ Instruction$-$k

What does the instruction do$?$

Where are the source and destination operands located?

What are the results?

Where are the results stored?

After you finish the assignment or at the end of the lab session: $1.$ show your experimental results to the lab assistant; $2.$ fill out the section below; $3.$ each member signs on the sign$-$out sheet that the lab assistant provides $($a member not present in the lab will not receive credits for the lab$).$

Group members present in the lab:

$\_$Date:

Lab report: $1.$ Screenshots of all your experiments; and $2.$ the filled$-$out lab assignment sheet with the required answers.