Second-Term Examination

Fifth Semester [B.Tech] - November 2006

Paper Code : ETEC – 301 Subject : DCS-II

Time : 1¹/₂ Hours

Maximum Marks : 30

Note : Attempt any 3 questions in all. Q1 is compulsory. Each question carries 10 marks.

Q1	( a )	What do you mean by delta delay?	1
	( b )	What are generics? Give examples.	2
	( c )	Differentiate between constants and variables?	2
	( d )	Write down a signal assignment statement (using the concatenation operator &) that creates a rotate right operation by 7 bit positions on the following signal: SIGNAL m : std_logic_vector(12 downto 0);	2
	( e )	What is the main function performed by OLMC's?	3

Q2	( a )	What are signal drivers? What is the effect of transport delay and inertial delay on the signal drivers?	6
	( b )	What are the types of object declarations used in VHDL?	4

( a )

Given the following entity declaration of a 2-to-4 decoder with an enable signal

ENTITY decoder IS
PORT(a, b, g: IN std_logic;
y: OUT std_logic_vector(3 DOWNTO 0));
END decoder;

Write down two architecture descriptions using

( b )

What is the general expression for case statement?

( c )

Implement BCD to gray code converter using PLA?

Q4		Write short notes on :	10
	( a )	DRAM interfacing
	( b )	Sequential PLD's
	( c )	Configuration specification
	( d )	VHDL simulation phases