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Monday 7 November 2022

Rising and Falling Edge Detector using Verilog

 In the real word, there might be many scenario that we need to detect rising edge or falling edge of the signal. If rising/falling edge happens on particular signal, then design can perform certain task. This rising or falling edge can be detected using following code. This code is done in Verilog language. In given below example code, clock clk, input signal sig_a, output rising edge signal ris_a and falling edge signal fal_a are defined. Both ris_a and fal_a are high for one clock cycle when circuit detects rising or falling edge on the sig_a respectively.

Sunday 13 May 2018

Get Familiar with System Task in Verilog

There are special Tasks and Function in Verilog language which are used to generate input and output during simulation process. These special Tasks and Functions are always starts with $ sign, followed by Task/Function specifier. Synthesis tools ignore these system tasks and functions.

These System Tasks are classified as below
  • Display Task
    • $display, $write, $monitor, $strobe
  • File I/O Task
    • $fopen, $fclose, $fdisplay, $fstrobe, $fmonitor
  • Timescale Task
    • $time, $stime, $realtime
  • Simulation Control Task
    • $reset, $finish, $stop

Friday 11 May 2018

Easy UVM (Universal Verification Methodology) Tutorial

UVM stands for Universal Verification Methodology. It is standard methodology to verify Integrated Circuits. UVM is derived from OVM, Open Verification Methodology. UVM is developed by Accellera with the support of Aldec, Cadence, Mentor Graphics and Synopsys. UVM is based on System Verilog language. With the help of UVM, engineers are able to create an efficient verification environment. It is portable from one project to another. Due to portability, engineers can reuse testbench from previous projects and modify different components as per their need. UVM easy tutorial is shown below. It is available on YouTube. It is developed by John Aynsley from Doulos. There are twenty videos. After watching this tutorial, overall picture of UVM will be cleared. 

Tuesday 13 June 2017

Verilog Code for (7,4) Systematic Hamming Encoder


Hamming code is useful in Error Correction in Linear Block Code. This code will encode four bits of data and generate seven bits of code by adding three bits as parity bits. It was introduced by Richard W. Hamming. This algorithm can detect one and two bit error and can correct one bit error. Given below code will generate (7,4) Systematic Hamming Encoder. This encoder will use Least Significant 4 bits as data inputs and Most 3 significant bits as a parity bits.

Sunday 2 October 2016

Design a Constant Divider using VHDL Coding.

Constant Divider circuit accepts an input of 8 bit wide and divides it by constant value 53. The divider circuit will generate two output values as remainder and quotient. As we know that the division operator is not synthesizable, so division is done by repetitive subtraction method. As an example of input is 108, the remainder is 2 and quotient is 2 while if input is 20, remainder is 20 and quotient is 0. In this design Inp is input with 8 bit long, Remi and Quo are two output signals with 6-bit and 3-bit long respectively. Here bit lengths of Remi and Quo are decided as per getting maximum value. Divider is constant which is 8 bit long and value is "00110101". Binary value of 53 is "00110101".