Digital Systems Design

566 n. E. (Computer Sc. Engg.) VIth Semester Examination DIGITAL SYSTEM DESIGN Paper-CSE-308-C Time allowed: 3 houd

Maximum Marks: 100

Note: Attempt any five questions. All parts of a question should be attempted at olle place. 1.

What is key difference between sequential and combinalional circuits? Design BCD to Excess-3 code convertor, using minimum number of NAND gates. 20

2.

(a)

Discuss the following with examples as are used 1/1 VHDL (i)

Data objects

4 "

(ii) Physical types

-,

(iii) 'Sub types

J

(iv) Difference between array and records types.

4

(b) What is meant by operator overloading? Give an example.

7

3. (a) What is the difference between function and procedure in VHDL? Give suitable examples, also discuss the use of function as a type conversion function. 12 (b) Draw the wave form for following VHDL code architecture N-E of 0 is.

8

signal Z : bit: = '0' ; begin

566-3,100-P2-(Q_8) (03)

PT.O.

( 2 ) z <= 'y' after 2ns, '0' after 5 ns, 'y'

after 10 ns ; Z <= '0' after 4 ns, 'I' after 5 ns, t

'0' after 20 ns; Z <= '1' after IOns; '0' after 20 ns; end N-E; 4.

Write

down

the

truth

table,

entity

declaration

and

behavioural/dataflow architecture for the following. Also draw the circuit and output waveforms:

5.

6.

(a) Encoder (of any size) (b)

1

Comparator (Bit)

0

Write down the truth table and VHDL code for the following. 1 Also draw the circuit and output waveforms: 0 (a) 4-bit left to right shift register (b)

1

4-bit up/down counter

0

1 What are the basic components of a micro computer? Explain briefly. Describe its processor implementation in VHDL. 20 0

7. (a) How can a ROM be used as a PLA') Write down its advantages. (b) Discuss briefly 22 V /0 PLD.

10 1 0

8. Write short notes on the following: (i) PAL 16L8 (ii) Various Loops in VHDL (iii) Packages.

566-3,100

7

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