Microprocessor (MPU)
includes ALU, register arrays, and control circuit on a single chip.
includes microprocessor, memory, and I/O signal on a single chip.
a computer that is designed using microprocessor as its CPU

Machine Language binary medium
Assembly Language programs written in mnemonics
Low-level Language
Machine and Assembly Language
High-level Language
programs written in English-like words, independent of a given computer.
Compiler translates HLL into ML
Interpreter translates HLL into ML
translates one statement at a time.
Assembler translates AL program into binary machine code
Manual Assembly a procedure of looking up the machine codes manually from the instruction set and entering those into the computer through a keyboard.
ASCII American Standard Code for Information Interchange.
7 bit alphanumeric code with 128 combinations.
each combination assigned to either a letter, decimal digit, a symbol, or a command.
Extended ASCII 8 bit alphanumeric code with 256 combinations.

Instruction ?
a binary pattern designed to perform a function inside a microprocessor.
Instruction set?
the entire group of Instructions.
determines what all function a Mpr can perform.
Addressing modes is the various ways of specifying data.
Opcode Format
In 8085, all operations, registers and status flags are identified with a specific code.
CODE Registers   CODE   Registers Pairs
00            0B            00          BC
00           1C             01          DE
01            0D           10           HL
01           1E             11          AF or SP
10           0H
10           1L
11          1A
110        Reserved for mem related opns.

Instructions - 5 functional categories:
Data transfer operations
Arithmetic operations
Logical operations
Branching operations and
Machine –control operations

1. Data Transfer Instructions
Mnemonics                      Examples                    Operation
MVI R, 8-bit data         MVI B, 4FH       Load 8 bit data in a register
MOV Rd, Rs                MOV B, A          Copy data from source register Rs into Rd

2. Arithmetic Instructions
The frequently used arithmetic operations are :
Increment (Add 1)
Decrement (Subtract 1)

3. Logic and Bit Manipulation Instructions
These instructions include the following operations:
X-OR (Exclusive OR)
Rotate Bits

4. Branch Instructions
The following instructions change the program sequence.

Mnemonics                          Examples                                      Operation
JMP 16-bit address           JMP 2050H            Change the program sequence to the specified 16-bit addr.
JZ 16-bit address              JZ 2080H                Change the program sequence to the specified 16bit
                                                                         address if the Zero flag is set

5. Machine Control Instructions
These instructions affect the operation of the processor
Mnemonics                  Examples                           Operation
HLT                                 HLT                        Stop processing and wait
NOP                               NOP                       Do not perform any opn

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.