Fundamentals of HDL - Dec 2013

Electronics & Communication (Semester 4)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Compare VHDL and verilog.(6 marks) 1 (b) What are values that std-logic (VHDL) and nets (verilog) can take?(6 marks) 1 (c) With proper example explain the logical operators of verilog.(8 marks) 2 (a) What are the facts of data flow description?(2 marks) 2 (b) Starting from the basic draw the logic symbol of D'latch excitation table. K map circuit for D latch and write VHDL and verilog program for the same.(10 marks) 2 (c) Write a data flow description (in both VHDL and verilog) of a full adder with enable. If the enable is low (0), the sum and carry are zero; otherwise the sum and carry are usual outputs of the adder. Use a 5 ns delay for any gate including xor. Draw the truth table of this addet and derive the Boolean function after minimization.(8 marks) 3 (a) With syntax explain different types if loops in VHDL and verilog.(10 marks) 3 (b) Write a program in VHDL and verilog for JK flip flop using if & else if statements.(10 marks) 4 (a) What is binding? Explain the binding between entity and components in VHDL and between two modules in verilog.(10 marks) 4 (b) Write VHDL behavioural description of a tristate buffer. Use this as a component for structural of 2 to 4 decoder with tristate output.(10 marks) 5 (a) Write VHDL procedure and verilog task for N-bit ripple carry adder.(10 marks) 5 (b) With suitable example write VHDL code for writing integers to a file.(10 marks) 6 (a) Give an example of a VHDL package.(8 marks) 6 (b) Write the block diagram and function table of a SRAM of 16×8 and write verilog code for the same.(12 marks) 7 (a) How to invoke a verilog module from a VHDL module? Giving an example of a full adder using two half adders.(10 marks) 7 (b) Discuss the facts and limitations of mixed language description.(10 marks) 8 (a) Draw the flow chart and explain the steps invoked in synthesis.(10 marks) 8 (b) Write a program in VHDL and obtain the gate level synthesis for BP ad ADH. BP is the input and ADH is the output. BP varies from 0 to 7 and ADH varies from 0 to 16. Assume that if BP is more than 5 the ADH is 0 for BP>2 and less than 5 the ADH is given by ADH=-5×BP+25.(10 marks)