8085:branching and logical instruction

1. MICROPROCESSOR AND ITS
INTERFACING
TOPIC:
INSTRUCTION SET:LOGICAL AND
BRANCHING INSTRUCTION AND
LOOP INSTRUCTIONS

2. INTRODUCTION
It is a binary pattern designed inside a
microprocessor to perform a specific
function.
The entire group of instruction
microprocessor supports is called
instruction set.
8085 has 246 instructions.

3. Logical instructions…
Logical operations are performed on
data stored registers , memory and
status flags.
The operations are:
•AND
•OR
•COMPARE
•XOR
•COMPLEMENT
•ROTATE

4. Any 8-bit data, or contents of registers or
contents of memory location can logically
have
 AND
example : ANA B (B is register)
ANA M (M is memory location
pointed by HL pair)
ANI 8 bit data
 OR
example :ORA B
ORA M
ORA 8 bit data

5.  XOR
example :XRA B
XRA M
XRI 8-bit data
With the contents of accumulator
• The results are stored in accumulator.

6. • ROTATE
Each bit in the accumulator can be
shifted left or right to next position.
Example: RLC
• COMPLEMENT
The contents of accumulator can be
complemented .Each 0 is replaced by 1
and each 1 by 0.
Example : CMA

7. COMPARE
Any 8-bit data or the contents of register
or contents of memory location can be
compared for
 Equality
 Greater than
 less than
With the contents of accumulator . The
results are reflected in status flags.
Example: CMP B
CMP M
CPI 8-bit data

9. EXAMPLE:
A MEMORY LOCATION 2202H CONTAINS
80H DATA .WRITE AN ALP TO CONVERT
THIS DATA TO 08H .STORE MODIFIED
RESULT INTO MEMORY LOCATION 2203H

11. BRANCHING
INSTRUCTIONS
 It alter the normal sequential flow.
 This instruction alters either
conditionally or unconditionally.

12.  These operations are used to control the
flow of program execution.
o CALL AND RETURN
Conditional call and conditional return
Unconditional call and unconditional
return
These instructions change the sequence
of the program either by calling a
subroutine or returning from a
subroutine.
Example: 1)unconditional call and return
CALL 2000H // call a subroutine

13. 2)Conditional call and conditional return
CNC 2050H // call a
subroutine with its 16 bit address if
carry flag is set.
RZ // return if zero flag is
set.

14. o JUMPS
Conditional jumps
Unconditional jumps
These test for certain conditions(zeros
or carry flag ) and alter the program
sequence when condition is met.
Example :JC 2080H // jump to 16 bit
address when carry flag is set
JMP 2050H // unconditional jump

15. EXAMPLE:
WRITE AN ALP TO FIND CUBE OF A
GIVEN NUMBER .STORE RESULT INTO
REGISTER B

17. Submitted by:
 Nemish (150130103017)
 Bhavin (150130103018)
 Deval (150130103020)
 Devanshi (150130103021)