The collector terminal is intermediately doped and collects electrons from the Base.Īn NPN type transistor is the composition of two N-type doped semiconductor materials between a P-type doped semiconductor layer as shown above. The Base terminal is lightly doped and passes the emitter-injected electrons onto the collector. The emitter is a heavily doped terminal and it emits the electrons into the Base region. The transistor has three terminals, namely Base, Emitter, and Collector. They are usually compiled into libraries and will be available for us to select within EDA tools at a later stage in the design process.Bipolar junction transistors are classified into to types
The simple example shown above illustrates how all the physical implementation details have been hidden while still providing a clear idea of how the counter functions.Ĭtr is a module that represents an up/down counter, and it is possible to choose the actual physical implementation of the design from a wide variety of different styles of flops optimized for area, power and performance. It also resets the counter if the signal rstn becomes 0 making this an active-low reset.
#TRANSISTOR DEFINITION FOR DUMMIES CODE#
The code essentially makes the counter count up if the up_down signal is 1, and down if its value is 0. For the time being, let us simply understand that the behavior of a counter is described. We will delve into more details of the code in the next article. The following code illustrates how a Verilog code looks like. Verilog helps us to focus on the behavior and leave the rest to be sorted out later. Power dissipation, timing and the ability to drive nets and other flops would also require a more thorough understanding of the physical characteristics of a transistor.
Verilog creates a level of abstraction that helps hide away the details of its implementation and technology.įor example, the design of a D flip-flop would require the knowledge of how the transistors need to be arranged to achieve a positive-edge triggered FF and what the rise, fall and clk-Q times required to latch the value onto a flop among many other technology oriented details. Today, Verilog is the most popular HDL used and practiced throughout the semiconductor industry. Verilog was developed to simplify the process and make the Hardware Description Language (HDL) more robust and flexible. VHDL was soon developed to enhance the design process by allowing engineers to describe functionality of the desired hardware and let automation tools convert that behavior into actual hardware elements like combinational gates and sequential logic. Bigger and complex circuits demanded more engineers, time and other resources and soon enough there was a need to have a better way of designing integrated circuits. In the early days of integrated circuits, engineers had to sit down and physically draw transistors and their connections on paper to design them such that it can be fabricated on silicon.
#TRANSISTOR DEFINITION FOR DUMMIES GENERATOR#
Introduction What is Verilog? Introduction to Verilog Chip Design Flow Chip Abstraction Layers Data Types Verilog Syntax Verilog Data types Verilog Scalar/Vector Verilog Arrays Building Blocks Verilog Module Verilog Port Verilog Module Instantiations Verilog assign statements Verilog assign examples Verilog Operators Verilog Concatenation Verilog always block Combo Logic with always Sequential Logic with always Verilog initial block Verilog in a nutshell Verilog generate Verilog Sequence Detector Verilog Pattern Detector Behavioral modeling Verilog Block Statements Verilog Assignment Types Verilog Blocking/Non-blocking Verilog Control Flow Verilog for Loop Verilog case Statement Verilog Functions Verilog Tasks Verilog Parameters Verilog `ifdef `elsif Verilog Delay Control Verilog Inter/Intra Delay Verilog Hierarchical Reference Gate/Switch modeling Gate Level Modeling Gate Level Examples Gate Delays Switch Level Modeling User-Defined Primitives Simulation Verilog Simulation Basics Verilog Timescale Verilog Scheduling Regions Verilog Clock Generator System Tasks and Functions Verilog Display tasks Verilog Math Functions Verilog Timeformat Verilog Timescale Scope Verilog File Operations Code Examples Hello World! Flops and Latches JK Flip-Flop D Flip-Flop T Flip-Flop D Latch Counters 4-bit counter Ripple Counter Straight Ring Counter Johnson Counter Mod-N Counter Gray Counter Misc n-bit Shift Register Priority Encoder 4x1 multiplexer Full adder Single Port RAM
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