…Its through the language and culture that a society breaths..
.. to understand the world of microprocessors and to communicate with them one must know their language and model…
The figure above shows the programming model of 8085 microprocessor.
LANGUAGE OF A MICROPROCESSOR:
Microprocessor cannot understand a program written in Assembly language.A program known
as Assembler is used to convert a Assembly language program to machine language.
Another general concept is that of an addressing mode. We have seen three addressing modes so far. They are:
1. Data Register Direct. The operand is in a register.
e.g., MOVE D0,D1 ;both operands
2. Immediate Data. The operand appears in the instruction.
e.g., MOVE #1,D1 ;left operand only
3. Absolute. The memory address of the operand appears in the instruction.
e.g., MOVE 1000,2000 ;both operands
The instruction set consists of 74 operation codes and 246 Instructions.The instructions can be
1.Data Transfer (Copy)
MOV-Move the contents of specified registers
OUT/IN -Copy between Input/Output Port and Accumulator
ADD-Add contents of specified register to Accumulator
SUB-Subtract a 8-bit number from Accumulator
ADI-Add a 8-bit number to accumulator
SUI-Subtract a 8-bit number from accumulator
INC-increment the contents of specified Register by 1
DCR-decrement the contents of specified Register by 1
3.Logical and Bit manipulation
AND two 8-bit numbers
OR two 8-bit numbers
Exclusive-OR two 8-bit numbers
Compare two 8-bit numbers
Rotate Left/Right Accumulator bits
Call & Return
•Conditional Call & Return
•Unconditional Call & Return
HLT Stop program execution
NOP Do not perform any operation