ENEE 244 (01**). Spring 2006

Homework 2

Due back in class on Monday, Feb 27.

1.  Represent the number 7429 in BCD code.

2.  Convert the BCD number 00110101 to decimal.

3.  State one advantage of the 2421 code over the regular (8421) BCD code.

4.  A transmitter using an even-parity scheme transmits the byte 01011011.

(a) What is the parity bit that is transmitted?

(b) Suppose during transmission only the parity bit is erroneously flipped because of interference.  Is this error detected at the receiver?

5.  How many distinct double-bit errors can occur in a 7-bit ASCII character? How many of these errors change the character's parity?  How many are detected?

6.  Determine whether the nor operator ~ defined by a~b = (a+b)' is associative, commutative, or distributive over +.

7.  We know that ac'.1 = ac'.  Write the dual of this equation.

8.  Simplify the 3-input boolean function Σ m(1,2,6,7) in terms of the inputs x, y and z.

9.  Express the 3-input boolean function Σ m(2,3,4,6) in maxterm canonical form.

10.  Use algebraic techniques to determine whether or not the following Boolean equation is valid:
(abd + a'b + b'd + c')(c + ab + bd)   =?       b(a+c)(a'+c') + d(b+c)