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Semester 6: DIGITAL ELECTRONICS AND MICROPROCESSOR 8085
Number Systems - Decimal, Binary, Octal, Hexadecimal and Conversions, Codes
Number Systems - Decimal, Binary, Octal, Hexadecimal and Conversions, Codes
Decimal Number System
The decimal number system is base 10, using digits from 0 to 9. It is the most commonly used number system for everyday counting and arithmetic operations.
Binary Number System
The binary number system is base 2, using digits 0 and 1. It is fundamental to digital electronics and computing as all computer data is represented in binary.
Octal Number System
The octal number system is base 8, using digits from 0 to 7. It is sometimes used in computing as a shorthand for binary since three binary digits can be represented by one octal digit.
Hexadecimal Number System
The hexadecimal number system is base 16, using digits from 0 to 9 and letters A to F. It is often used in programming and digital electronics as it can represent larger binary numbers more compactly.
Conversions between Number Systems
Conversions between number systems involve mathematical calculations. Common conversions include decimal to binary, binary to octal, and hexadecimal to binary.
Codes in Number Systems
Coding schemes like ASCII and Unicode utilize numerical representations for characters. These codes can be expressed using binary, octal, or hexadecimal formats, affecting storage and processing.
Boolean Algebra - Laws, De-Morgan's Theorem, Logic Gates, Minimization Techniques
Boolean Algebra
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Identity Law
The Identity law states that the operation of a variable with the identity element will yield the variable itself.
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Null Law
The Null law states that the operation of a variable with the null element will yield the null element.
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Idempotent Law
The Idempotent law states that the operation of a variable with itself will yield the variable.
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Complement Law
The Complement law states that a variable and its complement will yield the null element.
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Distributive Law
The Distributive law states that the operation of a variable with respect to AND and OR can be distributed accordingly.
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De Morgan's Theorems
De Morgan's theorems provide a way to express the complement of a conjunction or disjunction of variables.
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AND Gate
The AND gate performs a logical conjunction, yielding true if both inputs are true.
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OR Gate
The OR gate performs a logical disjunction, yielding true if at least one input is true.
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NOT Gate
The NOT gate performs a logical negation, yielding true if the input is false.
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Karnaugh Map
Karnaugh maps are a visual method for simplifying Boolean expressions.
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Quine-McCluskey Method
The Quine-McCluskey method is an algorithmic approach to minimizing Boolean functions.
Adders, Subtractors, Multiplexers, Encoders, Decoders
ADDERS, SUBTRACTORS, MULTIPLEXERS, ENCODERS, DECODERS
Adders
Adders are digital circuits that perform addition on binary numbers. They come in various forms, including half adders and full adders. Half adders add two single binary digits and output a sum and a carry bit, while full adders can add three binary digits, including carry from a previous addition. Adders are crucial in arithmetic logic units (ALUs) of processors.
Subtractors
Subtractors are circuits designed to perform subtraction. They can be classified as half subtractors and full subtractors. A half subtractor subtracts one binary digit from another and produces a difference and a borrow output. Full subtractors handle the subtraction of three inputs, including a borrow from a previous subtraction. They are vital for arithmetic operations in digital systems.
Multiplexers
Multiplexers, often referred to as data selectors, are devices that select one input from multiple inputs and forward the selected input to a single output line based on control signals. They are widely used in data routing and resource sharing in digital circuits, enabling efficient management of multiple data sources.
Encoders
Encoders are combinational circuits that convert data from one format to another, typically from multiple input lines to fewer output lines. A basic example is a binary encoder, which converts 2^n input lines into an n-bit binary representation. Encoders are essential for signal transmission and data compression.
Decoders
Decoders are combinational circuits that perform the inverse operation of encoders. They convert n binary input signals into one of the 2^n possible output lines. Decoders are used in applications like memory address decoding and data demultiplexing, enabling the selection of specific outputs based on input combinations.
Flip-Flops - Types, Registers, Counters, Memory Devices
Flip-Flops - Types, Registers, Counters, Memory Devices
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Flip-flops are basic building blocks of digital electronics used for storing binary data. Main types include SR flip-flop, JK flip-flop, D flip-flop, and T flip-flop. Each type has unique inputs and behavior.
Types of Flip-Flops
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Registers are small storage locations in a CPU used to hold temporary data and instructions. Flip-flops are used to create registers, with multiple flip-flops combined in parallel to store multiple bits.
Registers
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Counters are sequential circuits that count pulses. Types of counters include binary, decade, and up/down counters. They use flip-flops to count in binary and can include various configurations based on the application.
Counters
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Memory devices use flip-flops or variations such as SRAM to store data. They provide volatile storage, retaining data only when powered. Flip-flops enable fast access and writing of data, essential in computing.
Memory Devices
8085 Microprocessor - Architecture, Instruction Set, Addressing Modes, Assembly Language Programming
8085 Microprocessor
Architecture
The architecture of the 8085 microprocessor includes a 16-bit address bus, allowing it to access up to 64KB of memory. It has a 8-bit data bus, an ALU for arithmetic and logic operations, a set of general-purpose registers (B, C, D, E, H, L), a stack pointer, and a program counter. The control unit coordinates data flow between peripherals and memory.
Instruction Set
The 8085 instruction set is divided into five categories: data transfer instructions, arithmetic operations, logical operations, control instructions, and branching instructions. Each instruction specifies an operation performed on data that is stored in registers or memory.
Addressing Modes
The 8085 microprocessor supports various addressing modes such as immediate addressing, direct addressing, register addressing, register indirect addressing, and implied addressing. These modes define how the operands for the instructions are accessed.
Assembly Language Programming
Assembly language programming for the 8085 involves writing instructions in a symbolic format that corresponds to the machine code. Programs are created using mnemonics that represent specific operations, with syntax rules that organize these instructions into a complete program.
