ECET 105 help A Guide to career/Snaptutorial

ECET 105 Week 1 Homework
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1. Does a typical computer have any analog outputs? If so, what are they?
2. List three advantages of digital signal representation as compared to
their analog representation.
3. Convert 126 x 10+2 to scientific and engineering notations.
4. Make the following conversions:

a. Convert 0.34 seconds to milliseconds.
b. Express 0.0005 x 10-4 farads as picofarads.
5. The frequency of a signal is equal to the reciprocal of the signal’s
period (f = 1/p). For a computer with a 2.4 GHz clock, what is the clock
period? Use engineering notation for your answer.
6. The signal shown below is a sine wave as it might be displayed on an
oscilloscope. If it takes 40 msec. for the waveform to travel between the
points shown by the arrow “B” below, what is the frequency of the
waveform?
7. Power (in watts) is a certain amount of energy (in joules) divided by a
certain length of time (in seconds). The laser with the highest peak
power produces energy of 186 joules in 167 femtoseconds. What is the
peak power? Use engineering notation for your answer. (Note: Use
references to determine the value of a femtosecond and the proper
notation for your answer.)
8. Which logic function produces a HIGH output only when all of the
inputs are HIGH?
9. Which logic function produces a HIGH output only when all of the
inputs are LOW?
10. Using the Internet, find the data sheet for the 74LS00 integrated
circuit chip. Answer the following:
-----------------------------------------
ECET 105 Week 1 iLab Introduction to
Laboratory Test Equipment

I. OBJECTIVES
1. To learn the function and basic operation of the instruments
comprising a test bench
2. To gain a basic understanding of how to use the power supply,
DMM, oscilloscope, and function generator
3. To take measurements using the power supply, DMM,
oscilloscope, and function generator
4. To determine waveform characteristics of various signals
II. PARTS LIST
Equipment
IBM PC or Compatible with Windows 2000 or Higher
ELVIS II+
Parts

1 - 1.0 kohm Resistor (color bands = brown, black, red, gold)
1 - 4.7 kohm Resistor (color bands = yellow, violet, red, gold)
III. PROCEDURES
A. Introduction to Instruments and Measurements
Before beginning this lab, be sure that you have read the Lab Prepfor an
explanation of how to use the various instruments.
1. Measure DC voltage with the DMM.
a. Attach the power supply +5 V outputs to the DMM inputs.
b. Launch the ELVIS II+ DMM and select DC Voltage.
1. Press Run and record the reading below, including units.
2. Press Stop.
DMM measurement ___________________________
2. Measure DC voltage with the oscilloscope.
1. Launch the ELVIS II+
2. Enable Channel 0.
3. Ensure the following settings.
• Probe—10x
• Coupling—DC
• Scale—2 Volts/Div
• Vertical Position—0
• Timebase—50 us/Div
• Trigger Type—Immediate
• Trigger Source—Chan 0 Source
• Horizontal Position—50
• Acquisition Mode—Run Continuously
1. Connect the oscilloscope probe from the oscilloscope to the +5 V
output (main probe to +5 V and ground to GND).
2. Press Run and read the voltage on the oscilloscope. Record your
reading with the appropriate unit in engineering notation.
Vertical scale _____________ Horizontal scale______________
V = _____________
1. Press Stop.
3. Measure resistance with the DMM.

4. Remove a 1 kohm resistor (color bands are brown, black, red,
gold) from the parts kit. The first three bands indicate the value of the
resistor and the fourth band indicates the accuracy of the resistance. A
gold band indicates that the measured value should be within ±5% of the
specified value.
5. Switch the DMM to ohms (Ω) and measure the resistor value by
clipping the probes to each end of the resistor.
6. Press Start and record the measured value and the calculated
range (1 kohm ±5%) including units.
DMM measurement ____________________________
Theoretical range ______________________________
7. Repeat Step 3 with the 4.7 kohm resistor (color bands are yellow,
violet, red, and gold) including units.
DMM measurement ____________________________
Theoretical range ______________________________
8. Press Stop.
4. Measure a changing signal voltage with the oscilloscope.
9. Launch the ELVIS II+ frequency generator.
1. Connect the frequency generator output to the oscilloscope CH0
input.
2. Select the square wave output ( ) and set the frequency to 1
kHz.
5. Set the Amplitude to 5.00 Vpp and the DC Offset to 2.50 V.
6. On the oscilloscope, adjust the Time/Div setting to a value of 0.5
ms.
7. Set the Volts/Div to 2.0 V.
8. Press Run on both instruments. Sketch the observed waveform
below. Label both axes and ground.
Output Waveform for Step 4

1. Stop both instruments.
5. Generate and measure triangle waveforms.
2. Set the frequency generator to output a triangle wave ( ) with a
frequency of 1.0 kHz, 6.00 Vpp, and 0 V DC Offset.
3. Set the oscilloscope to 2.0 V/div and 200 μsec/div.
4. Run both instruments and sketch the output below. Label the
axes and ground.
Output Waveform for Step 5
1. Measure and record the values below, including units.
Period ________________ Frequency _________________
1. Stop both instruments.
6. Generating and measuring sinusoidal waveforms.
6. Select a sine wave output with a frequency of 1 kHz, 6.0 Vpp,
and 0 V DC Offset.
7. Record measurements displayed on the oscilloscope display,
including units.
Peak +V = ________________ Frequency = ________________
1. Component Identification
Go through your parts kit and identify the various components and tools
you have. Application and proper use will be demonstrated in video
clips and discussed in the Lab Q & A thread.
1.
2. After verifying that your lab kit is complete, select two
components and find out what they are and what they do. HINT—Use
the instruction manual, illustrated parts list, the campus library and/or
the Internet to guide you toward the answers. Record the part numbers
and functions below.
First device’s part number or physical description _________________
First device’s function (what does it do?)
Second device’s part number or physical description
_________________
Second device’s function (what does it do?)

1. TROUBLESHOOTING
Describe any problems encountered and how those problems were
solved.
-----------------------------------------

1. What is the duty cycle for a square wave signal that is HIGH for 15
nsec and LOW for 30 nsec?
2. A pulse train is shown on the oscilloscope below. Determine the
period of the pulse.
3. Determine the frequency for a pulse that occurs every 10 ms.
4. What is the base-10 value for the binary number 11012?
5. What are the respective weights of the 1s in Problem 4?
6. How many different values can be represented by 6 bits, 7 bits, 8 bits,
and 10 bits?
7. What is the minimum number of bits required to represent each of the
following decimal numbers: 10, 1,000, 100,000, and 1,000,000?
7. Convert the binary value, 1011010100101101, to a hexadecimal
equivalent.
9. Convert the following decimal numbers to 8-bit binary values. For
negative numbers, use the 2’ complement formulation.
10. Express each of the following signed numbers (2s complement
format) in decimal:
-----------------------------------------
ECET 105 Week 2 iLab Soldering Techniques
and the Electronic Die Kit

I. OBJECTIVES
1. To learn the basics of soldering.
2. To produce mechanically and electrically sound solder joints.
3. To assemble the Electronic Die Kit.
II. PARTS LIST
Equipment:
Digital Die Kit
Tools:
1 – Soldering Iron
1 – Pair Long-Nose Pliers
1 – Diagonal cutter
1 – Solder and hookup wire
1 – Wire stripper

III. PROCEDURE
1. Preparation
2. Prepare a well-ventilated and clear workspace with ample lighting.
3. Ensure that the workspace includes a mat to work on in order to
prevent the burning of the table or materials during the process.
4. Use a tray, egg crate, or vegetable/fruit tray for all (but especially the
small) parts to avoid losing them. Attach the tray with double-sided tape
to your bench or desktop.
5. Have a waste basket or desktop trash receptacle handy.
6. Ensure that the sponge that accompanies the soldering iron is
sufficiently damp. The level of dampness needed is judged by wetting
the sponge and then squeezing out the excess water until the sponge can
be held in the hand with no noticeable water dripping from it.
CAUTION:
In order to avoid injury to the eyes, goggles or other eye protection must
be worn AT ALL TIMES during the circuit assembly and soldering
process.
A soldering iron at temperature is very hot. It is a fire hazard. It is a
health hazard. Caution must be taken at all times to ensure that contact
with the skin does not occur.
6. Plug in the soldering iron and wait approximately five minutes for the
iron to heat to a proper temperature. The temperature of the iron may be
tested by lightly rubbing the tip of the iron against the moist sponge. If a
majority of water is evaporated, then the iron is ready for use. The tip
should be kept clean and tinned for soldering. The sponge is used to
wipe away excess solder and materials. Tinning means that there is
always a thin layer of solder on the tip.
7. Procure and prepare the dice kit for soldering. Inventory the parts and
materials and ensure that each part fits the circuit board correctly by
checking the parts on the board WITHOUT soldering them to the board.
Put them in the tray until ready to install.

8. Prepare the tools that you will need: soldering iron, rosin core solder,
desolder wick, safety glasses, long-nose pliers, and wire cutters.
1. Assembling the Electronic Die Kit
2. Start with the seven 220 ohm resistors. Note that the color bands are
red-red-brown-gold.
2. With your long-nose pliers, bend the legs of all seven of the resistors
so that they form 90-degree angles.
3. Insert the 220 ohm resistors into R1, R2, R3, R4, R5, R6, and R7 of
your printed circuit board through the side where you see the labels.
Bend the lead on the side away from the component part, not next to the
resistor body, but on the other side of the pliers. Otherwise, you may
break the connection inside the resistor. Ensure that all components,
with the exception of the IC socket, are not fully inserted in the board,
but have small gaps between them and the circuit board to avoid
excessive heating.
4. Prepare to solder the legs of the resistors to the bottom side of the
printed circuit board. Turn the board upside down. Caution must be
taken to ensure that the “eyelet” solder pads on the board are not stressed
with either hands or the tip of the iron during the heating process. The
eyelets are easily dislodged and, if damaged, may result in irreparable
damage to the circuit board.
In soldering, firmly touch the tip of the iron to the pad AND the lead you
want to solder. Ensure that only one wire and one pad (one connection)
is heated at a time. When the connection has been heated sufficiently (it
should take only a few seconds), touch the solder to the pad, opposite
from the tip of the iron, and allow a small amount of solder to flow onto
the connection. The parts should not move while you are heating them or
they will not form a good joint. Sloppy or careless heating may cause
multiple connections to be soldered together, causing damage to the
circuit board.

5. Care must be taken as to not apply too much solder because this will
result in a convex-shaped connection and, possibly, a cold solder joint.
Ideally, the solder should be melted by the connection, not the iron.
6. Remove the iron after ensuring that the solder has spread over the pad
and that the lead is sufficiently secured. A resulting concave shape
should be observed at the connection. Have your team member or
instructor verify proper connection.
7. Trim the excess leads, pointing into a paper or plastic waste bag or
basket. Metal clippings may fly far, fall into computer keyboards, or
otherwise pose as a shorting hazard.
8. Insert the two, 0.1μF ceramic capacitors into C1 and C2.
9. Solder the legs of the capacitors to the bottom side of the printed
circuit board and carefully cut off the excess leads.
1. Insert the 7805, 5-volt regulator into U1 following the drawing on the
printed circuit board. Push the component down carefully until it is fully
set. DO NOT force the IC all the way onto the board. Push the part
partially down and allow the leads to spread out. The result should be
that the part stands off the board as shown. Solder and carefully cut
excess leads.
2. Insert the 8-pin, IC socket into U2 following the drawing on the
printed circuit board. Solder two pins on diagonally opposite corners.
(Hold one pin with the heat sink clip or paper clip while soldering the
other.) Inspect and confirm that all pins are in the correct holes in the
PCB and the socket is seated on the board. Solder each pin and repair
any bridging before continuing.
2. Insert the momentary switch into S1 following the drawing on the
printed circuit board and solder the two contact pins.
3. Insert the seven red LEDs into D1, D2, D3, D4, D5, D6, and D7
following the drawing on the printed circuit board. PLEASE NOTE that
the longer lead of the LEDs is the anode and should go into the hole
marked with a + sign.
4. Insert the 9V battery connector into P1 and solder. You may insert the
battery leads from the bottom. This will make a neater assembly should

you decide to put the Dice in a case. It is VERY IMPORTANT that the
red wire is soldered into V+ and the black wire is soldered into V-.
5. Have a team member or your instructor inspect your board when you
have finished.
6. Completing and Testing the Kit
7. Inspect the Atmel ATTINY85-20PU microcontroller. Straighten any
severely bent pins, very slowly; otherwise, they could break. Align the
IC on your breadboard so that the dot in the top lefthand corner of the IC
is at the same end as the notch in the IC socket.
Insert the pins on one side, but do not press in, making sure that each pin
is started in its socket. Gently press the IC from the other side against the
pins started until the pins on the other side easily start in their sockets.
Double check that no pin is bent under or is outside of its intended
socket location. Press the IC into the socket, firmly but gently.
2. Attach the 9V battery firmly to the battery connector.
3. The die kit should resemble Figure 4.1 when assembly is completed.
The Atmel ATTINY85-20PU has been shipped with a program already
stored so that the die may be tested by connecting the 9V battery to the
connector, then pressing and holding the momentary switch and
releasing it. While the switch is pressed, the LEDs will blink in a
random pattern. When the switch is released, a randomly generated
number between 1 and 6 will be displayed on the LED die. Note any
performance issues.
Hints:
If the die is not working on the first try, turn it off by unplugging the
battery. Check for warm/hot components.
If the regulator U1 is hot, you have a short somewhere. Look for solder
shorts, incorrectly inserted components, and leads that may be touching
adjacent leads. Remove the shorting connection and try again.
-----------------------------------------

1. Determine the output X for the 2-input AND gate with the input
waveforms shown.
2. Determine the output X for the 2-input OR gate with the input
waveforms shown.
3. Determine the output X for the 2-input Exclusive-OR gate with the
input waveforms shown

4. Determine the output X for the 2-input NAND gate with the input
waveforms shown.
5. Is the output from the NAND gate shown in Problem 4 active-HIGH
or active-LOW? Why?
6. Download from a semiconductor manufacturer’s website (such as
ti.com) the data sheet for a DIP packaged quad NOR gate (74x02). What
pins does this chip use for the inputs to the first gate?
7. Draw a logic circuit that performs the following Boolean expression:
Y = A * B.
9. Which gate is represented by the truth table below?
10. Use a truth table to determine the function of the gate shown below.
-----------------------------------------
ECET 105 Week 3 iLab Introduction to Digital
Logic Gates

I. OBJECTIVES
To understand basic logic functions (AND, OR, and NOT) and their
complement used in Boolean algebra and digital logic design.
To test simple logic small-scale integration (SSI) integrated circuit (IC)
devices.
II. PARTS LIST
Equipment:
Parts:
1 – 74LS00 Quad 2-Input NAND Gate IC
1 – 74LS02 Quad 2-Input NOR Gate IC
1 – 74LS04 Hex INVERTER Gate IC
1 – 74LS08 Quad 2-Input AND Gate IC
1 – 74LS32 Quad 2-Input OR Gate IC

1 – 74LS86 Quad 2-Input XOR Gate IC
1 – Set of Four Single-Pole-Double-Throw (SPDT) Switches,
DIP Style
1 – 330 Ω resistor
1 – Light emitting diode (LED), red
III. PROCEDURE
OR Gate Operation
Using the Internet or the campus library, acquire a hard copy of a data
sheet for the 74LS32 quad 2-input OR gate. (HINT: Look at ti.com for
possible help.) One of the OR gates is shown below in Figure 5.1.
Figure 5.1 – 2-Input OR Gate
Fill in the Table 5.1 for ALL possible logic conditions, based on the
information found on the data sheet.
Input (Pin 1) Input (Pin 2) Output (Pin 3)
Table 5.1 - 2-Input OR Gate Theoretical Truth Table
Write the Boolean expression below for the relationship between the
device inputs (labeled as A and B) and output (labeled as Y).
OUTPUT Y = ____________________________
Construct the circuit shown in Figure 5.2 (a layout of the breadboard is
shown in Figure 5.3). Be sure that the flat side of the LED (called the
cathode) is connected to ground and that the 74LS32 is connected to
power and ground (Pins 14 and 7, respectively).
Figure 5.2 – OR Gate Test Circuit
Top View
Side View
Figure 5.3 – Breadboard Layout for Figure 5.2
Connect the circuit to verify the logic gate operation recording the input
and output voltages. Fill in Table 5.2below for ALL possible logic
conditions.

Table 5.2 - 2-Input OR Gate Measured Truth Table
Do the results match the manufacturer’s truth table? __________
(YES or NO)
AND Gate Operation
Acquire a hard copy of a data sheet for the 74LS08 quad 2-input AND
gate.
Figure 5.4 – 2-Input AND Gate
Fill in the truth table below for ALL possible logic conditions based on
the information found on the data sheet.
Table 5.3 - 2-Input AND Gate Theoretical Truth Table
OUTPUT Y = ____________________________
Construct the circuit shown in Figure 5.5 by replacing the 74LS32 from
Figure 5.2 with a 74LS08.
Figure 5.5 - 2-Input AND Gate Test Circuit
and output voltages. Fill in the truth table below for ALL possible logic
conditions.
Table 5.4 - 2-Input AND Gate Measured Truth Table
(YES or NO)
NAND Gate Operation
Acquire a hard copy of a data sheet for the 74LS00 quad 2-input NAND
gate.
Figure 5.6 – 2-Input NAND Gate
Fill in Table 5.5 for ALL possible logic conditions, based on the
information found on the data sheet.

Table 5.5 - 2-Input NAND Gate Theoretical Truth Table
OUTPUT Y = ____________________________
Figure 5.7 – 2-Input NAND Gate Test Circuit
conditions.
(YES or NO)
Exclusive-OR Gate Operation
Acquire a hard copy of a data sheet for the 74LS86 quad 2-input
exclusive-OR (XOR) gate.
Figure 5.8 – 2-Input XOR Gate
Fill in the truth table below for ALL possible logic conditions, based on
Table 5.7 - 2-Input XOR Gate Theoretical Truth Table
OUTPUT Y = ____________________________
Figure 5.9 – 2-Input XOR Gate Test Circuit
conditions.

(YES or NO)
NOR Gate Operation
Acquire a hard copy of a data sheet for the 74LS02 quad 2-input NOR
gate.
Figure 5.10 – 2-Input NOR Gate
Table 5.9 - 2-Input NOR Gate Theoretical Truth Table
OUTPUT Y = ____________________________
Construct the circuit shown in Figure 5.11. Note that the pin numbers for
inputs and outputs have changes from Figure 5.9 (output is now Pin 1,
inputs are on Pins 2 and 3).
Figure 5.11 – 2-Input NOR Gate Test Circuit
conditions.
Table 5.10 - 2-Input NOR Gate Measured Truth Table
(YES or NO)
NOT Gate Operation
Acquire a hard copy of a data sheet for the 74LS04 hex NOT gate.
Figure 5.12 – NOT Gate
Table 5.11 - NOT Gate Theoretical Truth Table
device input (labeled as A) and output (labeled as Y).
OUTPUT Y = ____________________________

Construct the circuit shown in Figure 5.13. Note that the pin numbers for
inputs and outputs have changes from Figure 5.11 (output is now Pin 2,
input is on Pin 1).
Figure 5.13 – 2-Input NOR Gate Test Circuit
conditions.
Input (Pin 1) Output (Pin 2)
Table 5.12 - NOT Gate Measured Truth Table
(YES or NO)
TROUBLESHOOTING
Describe any problems encountered and how those problems were
solved.
-----------------------------------------

2. Determine the Boolean expression for the circuit shown below.
3. The Boolean expression for an AND gate is . Does the expression also
describe an AND gate? Prove your answer.
4. Write the Boolean expression for the logic circuit shown below.
5. Develop the truth table for the circuit shown in Problem 4.
6. Develop the truth table for the circuit shown below.
7. Develop the Boolean expression for the circuit shown in Problem 6.
8. Draw a logic circuit using only NAND gates to implement the
following Boolean expression: Y =AB + C.
9. Develop a logic circuit, using only NAND gates, to implement a
circuit to meet the requirements of the truth table shown below.
10. Determine the Boolean description for the circuit shown below.
-----------------------------------------

ECET 105 Week 4 iLab Logic Circuit Design,
Simplification, Simulation, and Verification
Objectives:
To design a digital logic circuit using a truth table and sum-of-product
(SOP) formulation.

To use the MultiSim program to simplify, simulate, and test the circuit
operation.
To build and test the logic circuit to verify that the system performs as
expected.
Results:
Built a circuit board which would turn on the LED light and used
multisim and tools which would simplify to do so. Verified the truth
table to check and see if the vales are accurate.
-----------------------------------------

1. Determine the decimal value of each of the following unsigned binary
numbers:
2. Determine the decimal value of each of the following signed binary
numbers displayed in the 2’s complement form:
3. Determine the outputs (Cout, Sout) of a full-adder for each of the
following inputs:
4. The circuit below is an attempt to build a half-adder. Will the Cout
and Sout function properly? Demonstrate your rationale.
5. Determine the outputs for the circuit shown below. Assume that C0 =
0 for all cases.
6. Derive the Boolean equation for A = B, when A and B are 4-bit
numbers.
7. Complete the timing diagram below for a 2-bit adder. (10 points)
8. Answer the following:

What is the frequency of a periodic waveform with a period of 1.0 µsec?
How many bits are required to represent decimal numbers from -256 to
+255?
What is the largest positive number that can be represented by 10 signed
bits?
9. The full-adder shown below is tested under all input conditions as
shown. Is the circuit operating correctly? If not, what is the most likely
fault?
10. Using a 4-bit adder/subtractor, carry out the binary operations for 9 –
3 and 3 – 9. What can you conclude about the answers and the carry out
bit (C4)?
-----------------------------------------
ECET 105 Week 5 iLab Designing Adders and
Subtractors

Objectives:
The objectives are to reinforce the concepts of binary
addition/subtraction while using the Quartus II Programmable Logic
Tool as well as getting used to the program. We were also supposed to
build and test a simple adder/subtractor using the eSOC III Board.
Observations/Measurements:
Describe any problems you had with this week’s assignment.
1. In the simulation run of the four-bit adder, when we performed the
addition 5 + 3, we did not immediately have an output of 8 on SOUT.
What could be the cause of this?
2. If we changed the count period to 1000 nS for A and B, would this
correct the anomalies in Question 1? Why or why not?
3. How fast can your 4-bit adder/subtractor determine the sum or
difference of two numbers?

4. Use the simulation timing diagram to compare the worst case time to
do an operation with your adder/subtractor with the worst case using the
74LS283. State which operation takes the longest and list the time
required for both devices.
-----------------------------------------

1. When a HIGH is on the output of the decoding circuit below, what is
the binary code appearing on the inputs?
2. Write the Boolean equations for each of the following codes if an
active-LOW decoder output is required. The first decode is shown as an
example.
3. What are the active outputs of a BCD-to-7 segment decoder with an
input of 0100?
4. A 7-segment decoder/driver drives the display below. Using the
waveforms shown, determine the sequence of digits that appear on the
display.
5. Construct a truth table for an active-LOW output BCD (1-of-10)
decoder.
6. Derive the truth table for the Y output in the diagram below.
7. Derive the Boolean equation for the Y output in Problem 6.
8. For the multiplexer shown below, determine the output for the
following input state.
D0 = 0, D1 = 1, D2 = 1, D3 = 0, S0 = 1, S1 = 0.
9. Determine the function of the circuit shown below.
10. Write the Boolean equation for the circuit shown in Problem 9.
-----------------------------------------
ECET 105 Week 6 iLab Decoders and
Multiplexers

Objectives:
To learn about the operation of a BCD-to-seven-segment decoder
To learn about the operation of a seven-segment display
To learn about the operation of multiplexers
To build and test a multiplexed display circuit using both discrete
components and the eSOC III board
Questions:
Why are the 330 Ω resistors required for the discrete logic circuit, but
not for the MultiSim simulated circuit or the eSOC III circuit?
Create a partial truth table showing the requirements for a seven-
segment decoder to output a hexadecimal digit. This requires four input
bits and six output states, A – F. For each output state, show the
segments a-g. The output states for the inputs 0 – 9 are the same as for

the 74LS47 (see focus.ti.com). Use capital letters A, C, E, F and lower
case for b and d.
Why is the seven-segment display driven with an active-LOW signal
using discrete logic and an active-HIGH with the eSOC board?
-----------------------------------------

1. Sketch the Q output for the waveforms shown. Assume that Q starts
LOW.
2. Sketch the Q output for the circuit shown below. Assume that Q starts
LOW.
LOW.
LOW.
LOW.
LOW.
LOW.
8. Sketch the Q0 and Q1 outputs for the circuit shown below. Assume
that both Q0 and Q1 start LOW.
9. What is the output frequency for Q1 in the circuit shown below?
10. What is the output frequency for Q2 in the circuit shown below?
-----------------------------------------
ECET 105 Week 7 iLab Add-Subtractor using
Flip-Flops

I. OBJECTIVES
To test the operation of a 74LS74 D flip-flop and compare the operation
with the predicted behavior
To test the operation of a 74LS112 J-K flip-flop and compare the
operation with the predicted behavior
To measure propagation delays of a 74LS112 J-K flip-flop
To build and test an enhanced adder-subtractor
II. PARTS LIST
Equipment:
Quartus II Design Software—Version 9.1
Frequency Generator
Oscilloscope

Parts:
2 – 330 Ω resistors, ¼ W 2 – Red LEDs
1 – 74LS74 dual D flip-flop 1 – Green LED
1 – 74LS112 dual J-K flip-flop 1 – SPDT Switch, DIP
configuration
1 – eSOC III FPGA Board
III. PROCEDURE
A. Test the 74LS74 D Flip-Flop
Build the D flip-flop circuit shown in Figure 7.1. The LEDs are wired as
active-LOW since the flip-flop can supply more current in a low state
than in a high state. This means that the green LED is on when is HIGH
and the red LED indicates Q is HIGH. Remember to attach VCC to pin
14 and ground to pin 7.
Using the circuit, verify that the operation follows the truth table for this
device.
What happens when both and are set low?
Build the J-K flip-flop circuit shown in Figure 7.2. Remember to attach
VCC to pin 16 and ground to pin 8.
Using the circuit, verify that the operation follows the truth table for this
device.
Increase the pulse generator output to 1.0 MHz. Set the switches so that
all of the flip-flop inputs are high and remove the LEDs and resistors.
Using the oscilloscope, measure the propagation times for the Q output
from the active clock edge. Record the value below.
Using Quartus II, modify the circuit from Lab 5 as shown in Figure 7.3
by adding three 7474 D-flip-flip chips. Note that a clear function has
been added and that the flip-flop presets are inactive since they are tied
to +5V (labeled VCC).
Perform a simulation to verify the correct operation of the circuit. Note
that in this case, the CLOCK signal is not a periodic signal; the CLOCK
signal is a discrete signal occurring on a switch closure.

Assign pins to the inputs and outputs. Use the DIP switches for your
inputs (0-3 for A, 8-11 for B, 7 for CLEAR, 15 for ADDSUB), one of
the debounced pushbuttons for CLOCK and the red LEDs for outputs
(RD0-4).
Download you program to the eSOC III board and test the operation of
the circuit.
Photograph your final circuit for submission (online) or demonstrate
your circuit to your professor (onsite or blended).
Why is the condition when both and are LOW considered illegal?
How do the values you measured for tPHL and tPLH compare with
values specified in the 74LS112 data sheet? You may need to go online
to find this value.
Why were the LEDs removed before making the propagation delay
measurements?
-----------------------------------------

ECET 105 help A Guide to career/Snaptutorial

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