What are 8085 Microprocessor Instructions Categories

8085 microprocessor

The microprocessor (┬ÁP) 8085 is one of the most frequently used 8-bit microprocessors. Today it is of course completely out of date. But maybe it can be found in some training system or on a hobbyist's experiment board. Mostly it was replaced by a microcontroller, since the 8085 has no input and output interfaces or controls. As a workstation processor, he played no role. The processors from the x86 series have taken on this.

8 data and 16 address lines as well as some control and message lines are made available in time division multiplexing. Using a demultiplexer, standard peripherals can be connected to the address and data bus. With 40 connecting legs, this microprocessor is easily built into a microprocessor system together with special I / O and memory modules. The 8085 can address a maximum of 64 kbytes of memory and 256 input and output ports. Several interrupt lines are also provided.
Manufacturers of this processor are the companies Intel (development), Fujitsu, AMD, Mitsubishi, NEC, Oki, Siemens and Toshiba.

Facts

CPU8085
ManufacturerIntel
Clock rate3 - 6 MHz
year1976
Transistors6500
MIPS0,37
max. addressable64 kByte

Block diagram of the 8085

This is the block diagram of the 8085 microprocessor. Some unimportant details have been omitted in this figure. However, it shows the functional relationships sufficiently.

Arithmetic unit

Arithmetic-logical unit (ALU):
The ALU carries out all arithmetic and logical operations and calculations.

Intermediate register (buffer):
The 2nd operand for the ALU is stored in the intermediate register.

Accumulator:
The 1st operand for the ALU is stored in the accumulator. After the ALU has performed an arithmetic operation, the result is written to the accumulator.

Flags:
Register that has saved various states of the battery contents.

Command work

Command register:
The 8-bit wide command code is loaded into the command register.

Command decoder:
Every single bit of the command register is examined for its voltage state. This is used to determine which command is involved.

Time and sequence control:
This functional unit coordinates the time and logic signal sequences inside and outside (control bus) of the microprocessor.

Example of a program list

addresscontentmnem.hex.comment
0000DBIN 01DB01Processor reads the data from input port 01.
000101   
0002D3OUT 02D302Processor writes the data to output port 02.
000302   
0004C3JMP 0000C30000The program continues at the specified address.
000500   
000600   
0007xx   

Program execution of the 8085 microprocessor

TactAddress busData busControl buscomment
Reset0000DBMEMR / INSTRThe processor reads the command byte DB from memory location 0000.
1000101MEMRThe processor reads port address 01 from memory location 0001.
20101xxIORThe processor executes the input command.
30002D3MEMR / INSTRThe processor reads command byte D3 from memory location 0002.
4000302MEMRThe processor reads port address 02 from memory location 0003
50202xxIOWThe processor executes the output instruction.
60004C3MEMR / INSTRThe processor reads the command byte C3 from memory location 0004.
7000500MEMRThe processor reads the low byte of jump address 0000 from memory location 0005.
8000600MEMRThe processor reads the high byte of jump address 0000 from memory location 0006.

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The computer technology primer is a book about the basics of computer technology, processor technology, semiconductor memory, interfaces, data storage devices, drives and important hardware components.

I want that!