What to Submit

• Exercise 1 - all sections
• Exercise 2

Discussion, Hints & Tips

Exercise 1.1:

Straight forward. Just follow the instructions.

Exercise 1.2:

A name like Smith, John is turned into ID JSMITH

Exercise 1.3:

In this exercise you implement a spreadsheet that converts 8-digit (natural) binary numbers to decimal by using the formula found at the bottom of page 35 of the textbook. An 8-digit binary number has the form

and the formula is

In the terminology of the exercise, the named range value denotes the powers of 2, the named range bit holds the binary digits in the number and extension is the product of these two.

Notice that when you enter a number into input, i.e. cell B2, leading zeros are dropped. Transforming the input value to Normal form turns the input binary number into a string of exactly 8 zeros and ones including leading zeros. You can right-justify the Normal form so it looks like a number. (Numbers are right justified and text is left justified, by default.)

Take care in how you create the formulas you place in cells C6, C7 and C8.  Using the given named ranges you want to create formulas that can be copied by fill, right across columns C to J.

Exercise 2:

In this Exercise you write Excel formulas to simulate a 4-bit adder. This is equivalent to evaluating the formula at the bottom of page 35 of the textbook for n = 4,

where the 4-bit number is

Note that this notation is slightly different from the textbook, which uses subscripts 4 through 1, rather than 3 through 0.

In the exercise, two numbers, A and B, are added. Each is a 4-bit two's complement representation. Using the above notation,

where , the left-most digit, corresponds to the single cell named A3_, etc.

Two things need to be done:

1. the digits from A and B have to be extracted and placed in A3_, A2_, A1_, A0 and in B3_, B2_, B1_, B0.
   This is done using the functions LEFT, RIGHT or MID.
   For example, A3_ can be obtained by =LEFT(A,1)
   but this extracts a text character that only looks like a number. To convert it to a number you need to use the function VALUE(), so the final formula is




=VALUE(LEFT(A,1))



2. On the Adder worksheet you'll find a diagram for the 4-bit adder. Move it aside. Study the defined named ranges found on the Comments worksheet. Print out the diagram in the spreadsheet or use Figure 4.5 to label all the gates with these named ranges and the corresponding cell references. Then compare these with the labels in either Figure 4.4 or Figure 4.3.

One more issue. The logical functions, AND(), OR(), NOT() accept 0 or 1 as arguments but only produce TRUE/FALSE results. To convert these back to 0 or 1, use an IF().

The result of

=AND(x,y)

is either TRUE or False.

To convert the Boolean vaue to 1 or 0, use the formula as the Condition in an IF()...

=IF(AND(x,y),1,0)

Notice that you SHOULD NOT compare the result of the AND(). It is already TRUE/FALSE.