| (a) | Convert the numbers 25510 and 80110 to binary coded decimal (BCD) notation and perform BCD addition, leaving the
answer in BCD notation. Show all of your working.
|
[4] |
| (b) | Write the number -.062510 in floating point
format, with a 10-bit mantissa and a 6-bit exponent, both using 2's complement
representation.
|
[4] |
| (c) | Draw circuit diagrams to show how nand gates can be used to: | |
(i) produce the output  from an input
of A |
[1] | |
| (ii) produce the output A.B from inputs A and B | [1] | |
| (iii) produce the output A + B from
inputs A and B
|
[2] | |
| Label the inputs and outputs in each
diagram.
|
||
| (d) | A 2 to 4 decoder has two
inputs and four outputs:
Write down the truth table for this decoder. Draw and label a diagram to show how it could be implemented using a combination of and and not gates:
|
[4] |
| (e) | The diagram below shows a positive
level-triggered RS flip-flop and a positive edge-triggered RS flip-flop which share the
same pair of inputs and the same clock signal.
Complete the following timing diagram to show how the two outputs Qlevel and Qedge, both initially at zero, change during the four clock cycles:
|
[4] |
