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Thursday, 7 November 2013

Design Round Robin Arbiter using Verilog FSM Coding with Variable Slice Period


Sr. No.
Name of the Pin
Direction
Width
Description
1
Clk
Input
1
Clock Signal
2
Rst
Input
1
Reset Signal
3
Req
Input
4
4 Request Signals
4
Grant
Output
4
4 Grant Signals

Round-robin (RR) is one of the simplest scheduling algorithms for processes in an operating system. As the term is generally used, time slices are assigned to each process in equal portions and in circular order, handling all processes without priority (also known as cyclic executive). Round-robin scheduling is simple, easy to implement, and starvation-free. Round-robin scheduling can also be applied to other scheduling problems, such as data packet scheduling in computer networks. In this Arbiter, we have included one two bit counter. This counter will count no. of clock pulses for grant period of each request signal. In this if in between of counter, the request signal goes low, then grant will be given to other respective request signal and we can save that time slice.

Verilog Code for Vending Machine Using FSM

Sr. No.
Name of the Pin
Direction
Width
Description
1
Nw_pa
Output
1
News Paper Signal
2
Coin
Input
2
Only two Coins,
5 =2’b01
10 =2’b10
0 =2’b00
3
Clk
Input
1
Clock Signal
4
Rst
Input
1
Reset Signal

In this wending machine, it accepts only two coins, 5 point and 10 point. Whenever total of coins equal to 15 points, then nw_pa signal will go high and user will get news paper. It will not return any coin, if total of points exceeds 15 points.

Design Traffic Light Controller using Verilog FSM Coding and Verify with Test Bench

Given below code is design code for Traffic Light Controller using Finite State Machine(FSM). In this clk and rst_a are two input signal and n_lights, s_lights, e_lights and w_lights are 3 bit output signal. In output signal, "001" represents Green light, "010" represents Yellow light and "100" represents Red light. On the reset signal, design will enter into north state and start giving output after reset will go low. Design will turn on Green light for eight clock cycles and Yellow light for four clock cycles. Design will start with north, then goes into south, then east and finally into west and by this it will keep going.



Sr. No.
Name of the Pin
Direction
Width
Description
1
n_lights
Output
3
North Lights 
(001 = Green,
010 = Yellow, 100 = Red)
2
s_lights
Output
3
South Lights
(001 = Green,
010 = Yellow, 100 = Red)
3
e_lights
Output
3
Eight Lights 
(001 = Green,
010 = Yellow, 100 = Red)
4
w_lights
Output
3
West Lights
(001 = Green, 
010 = Yellow, 100 = Red)
5clkInput1Clock Signal
6
Rst_a
Input
1
Reset Signal

Verilog Code for Asynchronous Clear D-FlipFlop Using Primitive

Sr. No.
Name of the Pin
Direction
Width
Description
1
d
Input
1
Data input
2
clk
Input
1
Clock Signal
3
clear
Input
1
async clear  Signal
4
q
Output
1
Data Output

Verilog Code for 4x1 Multiplexer Using Primitive

Sr. No.
Name of the Pin
Direction
Width
Description
1
Ip
Input
4
Input to be muxed
2
Sel
Input
2
Select Lines
3
Op
Output
1
Muxed Output