The document describes instructions related to input/output, stack operations, and machine control for the 8085 microprocessor. It provides examples of programs for 8-bit division and calculating the square of a number using a lookup table. The division program uses subtraction and increment operations to repeatedly divide the dividend by the divisor until the remainder is obtained. The square program uses the lookup table at address 26H to find the square of the data in register L and store it in memory.

1. MICROPROCESSOR 8085
LECTURE 14
INSTRUCTION SET-VI
PROGRAMMING EXAMPLE-IV
PROF. SANDIP DAS

2. INSTRUCTION CLASSIFICATION
• Data Transfer group
• Arithmetic group
• Logical group
• Branch group
• Stack, I/O and Machine Control group

3. IN port addr Input to accumulator from I/O port T-states: 10 Flags affected: none
M-cycle-3
OUT port addr Output from accumulator to I/O port T-states: 10 Flags affected: none
M-cycle-3
PUSH rp Push the content of register pair to stack T-states-12 Flags affected: none
M-cycle-3
PUSH PSW Push the content of program status word T-states-12 Flags
affected: none M-cycle-3
POP rp Pop the content of register pair from stack T-states-12 Flags affected: none
M-cycle-3
POP PSW Pop the content of PSW pair from stack T-states-12 Flags affected: none
M-cycle-3
HLT Stops the execution of instruction T-states-12 Flags affected: none
M-cycle-3
XTHL Exchange stack top with H-L T-states-16 Flags affected: none
M-cycle-5
SPHL Move the contents of H-L pair T-states-6 Flags affected: none
M-cycle-1
EI Enable interrupts T-states-4 Flags affected: none
STACK, I/O AND MACHINE CONTROL
GROUP

4. WRITE A PROGRAM FOR 8 BIT DIVISION
Memory address Labels Mnemonics, operands Comments
2000 LDA 2501H Get divisor in
Accumulator
2003 MOV C,A Move divisor in
register C
2005 LDA 2500H Get dividend in
Accumulator
2008 MVI B,00H Initialize Counter
200A LOOP CMP C Compare Divisor and
Dividend. Is
Dividend>Divisor?
200C JC AHEAD
200F SUB C Subtract dividend from
divisor
2011 INR B Increment Quotient
2012 JMP LOOP Unconditional Jump
2015 AHEAD STA 2503H Store remainder in 2503H
2018 MOV A,B Move quotient in
register B
Suppose
2500H-08H (Dividend)
2501H-03H (Divisor)
Step 1:
A=03H, C=03H
New value of A=08H,B=00H
Comparing of A and C, since
A>C, so-
A=08H
- C=03H
05H
Now, Increment B, so B=01H
Again Compare A and C, A>C.
Repeat Step 1.
Step 2:
A=05H, C=03H, Subtracting
we get 02H, Increment B,
B=02H
Thus, 02H is remainder and
stored in 2503H.
B is moved to A and then
moved to 2502H as quotient.

5. WRITE A PROGRAM TO FIND SQUARE OF A NUMBER FROM LOOK
UP TABLE
Memory address Mnemonics, operands Comments
2000 LDA 2500H Get data in accumulator
2003 MOV L,A Get data in
register L
2004 MVI H,26H Get 26 in register H
2006 MOV A,M Square of data in
accumulator
2007 STA 2501H Store square in 2501H
200A HLT Halt
Data
2500H-07D
Result
2501H-49D
Look Up Table
Address
Square
(Hex) (Decimal)
2600 00
2601 01
2602 04
2603 09
2604 16
2605 25
2606 36
2607 49
2608 64
2609 81