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Reg. No. Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, JANUARY 2017
Course Code: EC 207
−− − −− Course Name: LOGIC CIRCUIT DESIGN (AE, EC)
Max. Marks: 100 Duration: 3 Hours

PART A (2x15=30)

(Answer two questions, Question no. 3 is compulsory)
1. a) Prepare a table for the first 12 integers in Binary, Grey, Excess 3 and ASCII. (4)
b) Perform the following operations [showing the intermediate steps]. (6)
i) 110002 - 101112 using 1’s and 2’s complement method 11)
74618 + 7157s 111) 0054೬ — 9830016 iv)
11001001101.10110112 into Decimal, Octal and Hexadecimal
c) What is Hamming code? How is the Hamming code word generated? The message
“1001001” is coded in the 7-bit even parity Hamming code, which is transmitted
through a noisy channel. Decode the message, assuming that at most a single error
occurred in each code word. (5)

2. a) A four variable Boolean function is given as=..+..+.. Where ...+...+... are
don’t cares. Use Karnaugh map to find the minimal SOP expression for F. Design and
realize the function F i) using
NAND gates only வாம்‌ ii) using NOR gates only. (8)
b) Design and realize a combinational circuit to compare two 3 bit numbers A (^ 24140)
and B (828180) as inputs and “AGT”’(A>B), “AEQ’(A=B) and
“ALT’(A
3. a) Perform each of the following conversions [show the intermediate steps]. (8)

(i) 160.6710 into Hexadecimal (01) A63.B516 into Decimal

(ii) ABBA into ASCII (iv) 12/0 into BCD
(111) 83510110 ASCII (vii) 28.310 into Ternary(Radix 3)
(iv) 241.325 into Decimal (viii) -8510 into 2’s complement

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