EE 231L Fall 2005
EE 231L Lab 2
Pre-Lab 2
1. Write an Altera TDF program to implement the majority circuit using Boolean logic.
2. Write an Altera TDF program to implement the majority circuit using one of the other design
methods — CASE statement, TABLE, or IF-THEN statements.
3. Compare the design of the ma jority circuit using discrete 74HC logic to that using a pro-
grammable logic device (PLD).
(a) How many chips are needed for each design?
(b) How much wiring is needed for each design? (About how many wires did you need when
you built the circuit using 74HC chips, and about how many will you need when you
build it using your PLD?)
(c) How much board space would be needed for the different designs?
(d) Discuss some of the advantages and disadvantages of using discrete 74HC chips vs. using
PLDs. Consider such things as board space (your PLD has 64 logic gates; each 74HC
chip has a few gates), design time, cost of chips (the PLD in your kit cost about $5.00,
vs. about $0.50 for each 74HC chip), power consumption (assume your PLD consumes
about the same power as each 74HC chip), ease of prototyping and troubleshooting,
ability to correct design errors, and anything else you can think of. When is it better to
use 74HC chips in a design, and when is it better to use 74HC chips?
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