Digital Electronics | Generated by AI
Absolutely! Here’s a comprehensive and approachable tutorial for Part II: Digital Electronics from Fundamentals of Electronic Technology (III). This part focuses on how digital systems represent, process, and manipulate binary information.
🔹 Part II: Digital Electronics
5. Fundamentals of Digital Circuits
a. Number Systems and Codes
- Binary (Base-2): Uses digits 0 and 1. Most fundamental to digital systems.
- Octal (Base-8) and Hexadecimal (Base-16): Shortcuts for binary groups (3 or 4 bits).
- BCD (Binary-Coded Decimal): Each decimal digit is represented separately in binary (0000–1001).
- Gray Code: Only one bit changes at a time between successive values—used in position encoders.
b. Boolean Algebra and Logic Gates
- Boolean Operations:
- AND: A·B = 1 if both are 1
- OR: A + B = 1 if either is 1
- NOT: 𝑨̅ = inverse of A
- Derived Gates:
- NAND, NOR, XOR, XNOR
- Combinational Logic: Output depends only on current inputs.
- Use truth tables and Karnaugh Maps (K-Maps) for simplification.
c. TTL and CMOS Integrated Circuits
- TTL (Transistor-Transistor Logic):
- Faster but consumes more power.
- Logic level 1: ~5V; level 0: ~0V.
- CMOS (Complementary Metal-Oxide-Semiconductor):
- Low power, slower speed, very common in modern ICs.
- Compatible with wide voltage ranges.
6. Combinational Logic Circuits
a. Analysis and Design
- Start with a truth table.
- Derive a Boolean expression.
- Simplify it (using Boolean laws or K-Map).
- Draw the logic circuit.
b. Common Modules
- Encoders: Convert 2ⁿ input lines to n-bit output (e.g., 8-to-3 encoder).
- Decoders: Opposite of encoder, used in memory address decoding.
- Multiplexers (MUX): Select one of many inputs.
- E.g., 4-to-1 MUX: 2 select lines, 4 inputs → 1 output.
- Demultiplexers (DEMUX): One input routed to one of many outputs.
c. Hazards
- Static Hazard: Output momentarily changes due to gate delays.
- Dynamic Hazard: Multiple glitches in output due to timing mismatch.
- Elimination: Use redundant logic or synchronous designs.
7. Sequential Logic Circuits
a. Flip-Flops (FFs)
- RS Flip-Flop: Set-Reset, simple memory.
- D Flip-Flop: Data or Delay FF, most common.
- JK Flip-Flop: Versatile; avoids invalid state of RS.
- T Flip-Flop: Toggles on clock; used in counters.
b. Counters and Shift Registers
- Counters:
- Asynchronous (Ripple): Clock is passed sequentially; slower.
- Synchronous: All FFs clocked together; faster.
- Types: Up, Down, Up/Down.
- Shift Registers:
- Store and shift bits serially or in parallel.
- Types: SISO, SIPO, PISO, PIPO.
c. Sequential Circuit Analysis
- State Tables/Diagrams: Show transitions between states.
- Use FF excitation tables to analyze and design.
- Synchronous is easier to control and debug than asynchronous.
8. Programmable Logic Devices (PLDs)
a. Types of PLDs
- PAL (Programmable Array Logic): Fixed OR, programmable AND.
- GAL (Generic Array Logic): Reprogrammable PAL.
- FPGA (Field Programmable Gate Array):
- Highly configurable.
- Thousands/millions of logic blocks.
- Used in complex systems like digital signal processing, video processing, etc.
b. Introduction to HDL (VHDL/Verilog)
- HDL (Hardware Description Language):
- VHDL: Verbose and strongly typed.
- Verilog: Compact and C-like syntax.
- Used to model digital systems at various levels (gate, register transfer, behavioral).
c. Logic System Design Examples
- Example 1: 4-bit binary counter in Verilog.
- Example 2: Simple traffic light controller with FSM (Finite State Machine).
- Example 3: ALU (Arithmetic Logic Unit) with basic operations.
Would you like diagrams, truth tables, or code snippets (e.g., in Verilog or VHDL)? I can also give you practice problems, cheat sheets, or quizzes for review. Let me know how deep you want to go!