ADDRESSING MODES & INSTRUCTION FORMAT OF INTEL 8085



The 8085 have 74 basic instructions and 246 total instructions. The instruction set of 8085 is defined by the manufacturer Intel Corporation. Each instruction of 8085 has 1 byte opcode. With 8 bit binary code, we can generate 256 different binary codes. In this, 246 codes have been used for opcodes.












The size of 8085 instructions can be 1 byte, 2 bytes or 3 bytes.

•    The 1-byte instruction has an opcode alone.

•    The 2 bytes instruction has an opcode followed by an eight-bit address or data.

•    The 3 bytes instruction has an opcode followed by 16 bit address or data. While storing the 3 bytes instruction in memory, the sequence of storage is, opcode first followed by low byte of address or data and then high byte of address or data.


ADDRESSING MODES

Every instruction of a program has to operate on a data. The method of specifying the data to be operated by the instruction is called Addressing. The 8085 has the following 5 different types of addressing.

1. Immediate Addressing
2. Direct Addressing
3. Register Addressing
4. Register Indirect Addressing
5. Implied Addressing

Immediate Addressing

In immediate addressing mode, the data is specified in the instruction itself. The data will be apart of the program instruction. All instructions that have ‘I’ in their mnemonics are of Immediate addressing type.

Eg. MVI B, 3EH  - Move the data 3EH given in the instruction to B register.


Direct Addressing
In direct addressing mode, the address of the data is specified in the instruction. The data will be in memory. In this addressing mode, the program instructions and data can be stored in different memory blocks. This type of addressing can be identified by 16-bit address present in the instruction.

Eg. LDA 1050H  - Load the data available in memory location 1050H in accumulator.


Register Addressing

In register addressing mode, the instruction specifies the name of the register in which the data is available. This type of addressing can be identified by register names (such as ‘A’, ‘B’, … ) in the instruction.

Eg. MOV A, B -Move the content of  B register to A register.


Register Indirect Addressing

In register indirect addressing mode, the instruction specifies the name of the register in which the address of the data is available. Here the data will be in memory and the address will be in the register pair. This type of addressing can be identified by letter ‘M’ present in the instruction.

Eg. MOV A, M - The memory data addressed by HL pair is moved to A register.


Implied Addressing

In implied addressing mode, the instruction itself specifies the type of operation and location of data to be operated. This type of instruction does not have any address, register name, immediate data specified along with it.

Eg. CMA - Complement the content of accumulator.



Posted by at
Labels:

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)

Labels

PROJECTS 8086 PIN CONFIGURATION 80X86 PROCESSORS TRANSDUCERS 8086 – ARCHITECTURE Hall-Effect Transducers INTEL 8085 OPTICAL MATERIALS BIPOLAR TRANSISTORS INTEL 8255 Optoelectronic Devices Thermistors thevenin's theorem MAXIMUM MODE CONFIGURATION OF 8086 SYSTEM ASSEMBLY LANGUAGE PROGRAMME OF 80X86 PROCESSORS POWER PLANT ENGINEERING PRIME MOVERS 8279 with 8085 MINIMUM MODE CONFIGURATION OF 8086 SYSTEM MISCELLANEOUS DEVICES MODERN ENGINEERING MATERIALS 8085 Processor- Q and A-1 BASIC CONCEPTS OF FLUID MECHANICS OSCILLATORS 8085 Processor- Q and A-2 Features of 8086 PUMPS AND TURBINES 8031/8051 MICROCONTROLLER Chemfet Transducers DIODES FIRST LAW OF THERMODYNAMICS METHOD OF STATEMENTS 8279 with 8086 HIGH VOLTAGE ENGINEERING OVERVOLATGES AND INSULATION COORDINATION Thermocouples 8251A to 8086 ARCHITECTURE OF 8031/8051 Angle-Beam Transducers DATA TRANSFER INSTRUCTIONS IN 8051/8031 INSTRUCTION SET FOR 8051/8031 INTEL 8279 KEYBOARD AND DISPLAY INTERFACES USING 8279 LOGICAL INSTRUCTIONS FOR 8051/8031 Photonic Transducers TECHNOLOGICAL TIPS THREE POINT STARTER 8257 with 8085 ARITHMETIC INSTRUCTIONS IN 8051/8031 LIGHTNING PHENOMENA Photoelectric Detectors Physical Strain Gage Transducers 8259 PROCESSOR APPLICATIONS OF HALL EFFECT BRANCHING INSTRUCTIONS FOR 8051/8031 CPU OF 8031/8051 Capacitive Transducers DECODER Electromagnetic Transducer Hall voltage INTEL 8051 MICROCONTROLLER INTEL 8251A Insulation Resistance Test PINS AND SIGNALS OF 8031/8051 Physical Transducers Resistive Transducer STARTERS Thermocouple Vacuum Gages USART-INTEL 8251A APPLICATIONs OF 8085 MICROPROCESSOR CAPACITANCE Data Transfer Instructions In 8086 Processors EARTH FAULT RELAY ELECTRIC MOTORS ELECTRICAL AND ELECTRONIC INSTRUMENTS ELECTRICAL BREAKDOWN IN GASES FIELD EFFECT TRANSISTOR (FET) INTEL 8257 IONIZATION AND DECAY PROCESSES Inductive Transducers Microprocessor and Microcontroller OVER CURRENT RELAY OVER CURRENT RELAY TESTING METHODS PhotoConductive Detectors PhotoVoltaic Detectors Registers Of 8051/8031 Microcontroller Testing Methods ADC INTERFACE AMPLIFIERS APPLICATIONS OF 8259 EARTH ELECTRODE RESISTANCE MEASUREMENT TESTING METHODS EARTH FAULT RELAY TESTING METHODS Electricity Ferrodynamic Wattmeter Fiber-Optic Transducers IC TESTER IC TESTER part-2 INTERRUPTS Intravascular imaging transducer LIGHTNING ARRESTERS MEASUREMENT SYSTEM Mechanical imaging transducers Mesh Current-2 Millman's Theorem NEGATIVE FEEDBACK Norton's Polarity Test Potentiometric transducers Ratio Test SERIAL DATA COMMUNICATION SFR OF 8051/8031 SOLIDS AND LIQUIDS Speed Control System 8085 Stepper Motor Control System Winding Resistance Test 20 MVA 6-digits 6-digits 7-segment LEDs 7-segment A-to-D A/D ADC ADVANTAGES OF CORONA ALTERNATOR BY POTIER & ASA METHOD ANALOG TO DIGITAL CONVERTER AUXILIARY TRANSFORMER AUXILIARY TRANSFORMER TESTING AUXILIARY TRANSFORMER TESTING METHODS Analog Devices A–D BERNOULLI’S PRINCIPLE BUS BAR BUS BAR TESTING Basic measuring circuits Bernoulli's Equation Bit Manipulation Instruction Buchholz relay test CORONA POWER LOSS CURRENT TRANSFORMER CURRENT TRANSFORMER TESTING Contact resistance test Current to voltage converter DAC INTERFACE DESCRIBE MULTIPLY-EXCITED Digital Storage Oscilloscope Display Driver Circuit E PROMER ELPLUS NT-111 EPROM AND STATIC RAM EXCITED MAGNETIC FIELD Electrical Machines II- Exp NO.1 Energy Meters FACTORS AFFECTING CORONA FLIP FLOPS Fluid Dynamics and Bernoulli's Equation Fluorescence Chemical Transducers Foil Strain Gages HALL EFFECT HIGH VOLTAGE ENGG HV test HYSTERESIS MOTOR Hall co-efficient Hall voltage and Hall Co-efficient High Voltage Insulator Coating Hot-wire anemometer How to Read a Capacitor? IC TESTER part-1 INSTRUMENT TRANSFORMERS Importance of Hall Effect Insulation resistance check Insulator Coating Knee point Test LEDs LEDs Display Driver LEDs Display Driver Circuit LM35 LOGIC CONTROLLER LPT LPT PORT LPT PORT EXPANDER LPT PORT LPT PORT EXTENDER Life Gone? MAGNETIC FIELD MAGNETIC FIELD SYSTEMS METHOD OF STATEMENT FOR TRANSFORMER STABILITY TEST METHODS OF REDUCING CORONA EFFECT MULTIPLY-EXCITED MULTIPLY-EXCITED MAGNETIC FIELD SYSTEMS Mesh Current Mesh Current-1 Moving Iron Instruments Multiplexing Network Theorems Node Voltage Method On-No Load And On Load Condition PLC PORT EXTENDER POTIER & ASA METHOD POWER TRANSFORMER POWER TRANSFORMER TESTING POWER TRANSFORMER TESTING METHODS PROGRAMMABLE LOGIC PROGRAMMABLE LOGIC CONTROLLER Parallel Port EXPANDER Paschen's law Piezoelectric Wave-Propagation Transducers Potential Transformer RADIO INTERFERENCE RECTIFIERS REGULATION OF ALTERNATOR REGULATION OF THREE PHASE ALTERNATOR Read a Capacitor SINGLY-EXCITED SOLIDS AND LIQUIDS Classical gas laws Secondary effects Semiconductor strain gages Speaker Driver Strain Gages Streamer theory Superposition Superposition theorem Swinburne’s Test TMOD TRANSFORMER TESTING METHODS Tape Recorder Three-Phase Wattmeter Transformer Tap Changer Transformer Testing Vector group test Virus Activity Voltage Insulator Coating Voltage To Frequency Converter Voltage to current converter What is analog-to-digital conversion Windows work for Nokia capacitor labels excitation current test magnetic balance voltage to frequency converter wiki electronic frequency converter testing voltage with a multimeter 50 hz voltages voltmeter

Search More Posts

Followers