Ateneo de Naga University College of Engineering ECE /CpE Department Engr. Gilbert D. Detera
Logic Circuits and Switching Theory ECEM323 LABORATORY MANUAL
TOC
i TABLE OF CONTENTS
TOC
i TABLE OF CONTENTS
Activity 1
7-SEGMENT LED DISPLAY DECODER
Activity 2
SEVEN SEGMENT DRIVER/DECODER and ENCODER
Activity 3
MULTIPLEXER AND MAGNITUDE COMPARATOR
Activity 4
BCD ADDER
Activity 5
LATCH AS A MEMORY DEVICE
Activity 6
COUNTERS USING FLIP-FLOPS
Activity 7
SHIFT REGISTERS
Activity
1 7-SEGMENT LED DISPLAY DECODER
INFORMATION Boolean Algebra is a mathematical expression that solve logical operation to its equivalent algebraic equation. The binary operations (+) stands for logic al OR and (·)stands for logical AND. This is some basic laws of Boolean algebra: x + (x · y) = x x · (x + y) = x x + x = 1 x · x = 0 Multisim Logic Converter is a tool that assists users to convert the truth table to its corresponding logic expression including: conversion of truth table to its boolean expression, conversion of boolean expression to its truth table, simplified boolean expression, conversion of a boolean expression to its equivalent circuit, and conversion of a boolean expression to its circuit using only NAND gates. seven-seg_segment_id.gif A seven segment display, as its name indicates, is composed of seven elements. Individually on or off, they can be combined to produce simplified representations of numerals.
The seven segments are arranged as a rectangle of two vertical segments on each side with one horizontal segment on the top, middle, and bottom. Additionally, the seventh segment bisects the rectangle horizontally. There are also fourteen-segment displays and sixteen-segment displays (for full alphanumerics); however, these have mostly been replaced by dot-matrix displays.
7-segment Light Emitting Diode decoder provides way of displaying information or digital data in the form of numbers, letters or even alpha-numeri cal characters. Some applications of it are digital clocks, electronic meters, and o ther electronic devices for displaying numerical information. There are two important types of 7-segment LED digital display: . The Common Cathode Display (CCD) - In the common cathode display, all the cathode connections of the LED's are joined together to logic "0" and the individual segments are illuminated by application of a "HIGH", logic "1" signal to the individual Anode terminals. E:\Switay\Second Sem 2010-2011\Logic 1\7 segment.bmp . The Common Anode Display (CAD) - In the common anode display, all the anode connections of the LED's are joined together to logic "1" and the individual segments are illuminated by connecting the individual Cathode terminals to a "LOW", logic "0" signal.
OBJECTIVES . To design the truth table of common cathode seven-segment LED display decoder using logic zero as an output for unused states. . To apply Boolean Algebra in generating the seven-segment LED display decoder equations and simplifying the logic expressions from the given truth table. . To get acquainted with the Logic Converter feature of Multisim 11 as an alternative tool in generating and simplification of Boolean equation from the given truth table. . To construct a common cathode seven-segment LED display decoder diagram through Multisim 11, indicating the numbers 0-9.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Construct a truth table having 4 inputs and 7 outputs indicating every segment of the common cathode LED display. Table 1 serves as an example.
2. In the truth table for FIGURE ZERO, segments a, b, c, d, e and f should all be ON while segment g is OFF. For FIGURE ONE, b and g should be ON while the rest are OFF.
3. Complete the table for numbers 3 up to 9.
4. Using Boolean Algebra, generate the equations for segments a, b, c, d, e, f and g. Write the simplified equations in Table 2.
. Note: Be reminded that for the common cathode configuration, 0 means OFF and 1 means ON.
Lab Proper 1. Using Logic converter on the Multisim 11,
place 4 inputs (A, B, C, D) and plug-in the binary codes of every output from a-g. In this activity, use 0 instead of x in output 10-15.
2. Using the truth table to simplified equation button of Logic Converter, generate the equations for segments a, b, c, d, e, f and g. Write the simplified equations in Table 3. 3. For every output (a-g) accomplished, generate the corresponding logic circuits and connect every output to its LED terminal. 4. For the input side of the logic circuits, connect pins A, B, C, and D respectively and assign an SPDT switch for each. After which, connect a 5V VCC. 5. Test the circuit by turning on/off the different switch combinations.
FOLLOW UP ACTIVITY Following the same concept and procedure in this activity, do the sevensegment common anode configuration. . Note: LED terminal assignments of the common anode configuration are just the opposite of the common cathode arrangement.
TABLES
A B C D
a b c d e f g 0
0 0 0 0
1 1 1 1 1 1 0
1
0 0 0 1
0 1 1 0 0 0 0 2
0 0 1 0
1 1 0 1 1 0 1 3
0 0 1 1
4
0 1 0 0
5
0 1
0 1
6
0 1 1 0
7
0 1 1 1
8
1 0 0 0
9
1 0 0 1
Table 1 Segment
Boolean Equation (Boolean Algebra) a
b
c
d
e
f
g
Table 2 Segment
Boolean Equation (Logic Converter) a
b
c
d
e
f
g
Table 3
SCHEMATIC DIAGRAM Draw the complete schematic diagram here: -4 SPDT connected either to supply voltage Vcc (as logic 1 input) or ground (as logic 0 input) -Decoder circuit: segment a, b, c, d, e, f and g diagram -Output display: 7-segment display or 7-LEDs or 7-logic probes
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
2 SEVEN SEGMENT DRIVER/DECODER and ENCODER
INFORMATION The 7-segment display which includes the encoder and the decoder is being used in many different ways. Because it has many uses and resources are limited, we must be aware that in constructing it, there are ways on how to simplify the equations, reduce the number of gates and ICs (Integrated Circuits) to be used. A decoder as observed on the previous laboratory activity is composed of the gate combinations that each corresponds to a particular output connected to the LED display and inputs connected to the switches. As to the encoder, it is a device designed to make a more efficient way to give commands as to what the 7-segment display must show, for example if the user press 4 on the keyboard the number 4 will also be displayed. The introduction of the method DON T CARE X had made it much simpler to do the decoder. Through this everything was reduced to its simplest form and interconnection of circuits having the same or repeated equation part was made possible. OBJECTIVES . To design the truth table of common cathode seven-segment LED display decoder using don t care (x) as an output for unused states. . To apply Boolean Algebra in generating the seven-segment LED display decoder equations and simplifying the logic expressions from the given truth table. . To learn more about reducing the number of gates in a circuit for the 7 segment decoder. . Derive the simplified Boolean expressions for the encoder circuit. . Construct logic circuits manually given only the Boolean expressions. . Combining the encoder and the same concept of decoder on the previous activity, light up the seven segment display by encoding, this time, the number 0-9. . To learn more about reducing the number of gates in a circuit for the 7 segment decoder.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Construct a truth table for 7-segment common cathode display decoder similar to that of the previous activity, observing that the output 10-15 now bears the value of don t care (x). Table 1 serves as an example. Complete the table for numbers 3 up to 9. 2. Using Boolean Algebra, generate the equations for segments a, b, c, d, e, f and g. Write the simplified equations in Table 2. 3. Research the truth table of 10-line to 4-line priority encoder. Write the corresponding output equations in Table 3.
Lab Proper 1. Using the Logic Converter of Multisim 11, generate the output equations of decoder (a, b, c, d, e, f and g) from the values of Table 1. Write the simplified equations in Table 4. 2. Construct the decoder diagram using Multisim 11 to create the 7 combinations of logical gates, each corresponding to the output equations in Table 4. Don t use the logic converter to generate the equivalent diagram. 3. With the 7 set of logical gates construct, simplify the diagram by combining those having the same part of equation. Replace it with a sub circuit and connect the pins into their respective inputs and outputs. Label it as decoder. 4. Based from the simplified equations in Table 3, do the same procedure to construct the diagram of priority encoder. Label it as encoder. 5. Connect the output of the encoder to the input of decoder, and the output of decoder to the input of the indicator. . Note: Observe proper component labeling. Avoid name repetitions.
6. Connect each input of the encoder with SPDT switch and connect it all to a 5v VCC. 7. Test the circuit by switching on each switch to get the desired numerical output.
FOLLOW UP ACTIVITY Following the same concept and procedure in this activity, do the sevensegment common anode configuration. . Note: LED terminal assignments of the common anode configuration are just the opposite of the common cathode arrangement.
RESULTS TABLES:
A B C D
a b c d e f g 0
0 0 0 0
1 1 1
1 1 1 0 1
0 0 0 1
0 1 1 0 0 0 0 2
0 0 1 0
1 1 0 1 1
0 1 3
0 0 1 1
4
0 1 0 0
5
0 1 0 1
6
0 1 1 0
7
0 1 1 1
8
1 0 0 0
9
1 0
0 1
10
1 0 1 0
x x x x x x x 11
1 0 1 1
x x x x x x x 12
1 1 0 0
x x x x x x x 13
1 1 0 1
x
x x x x x x 14
1 1 1 0
x x x x x x x 15
1 1 1 1
x x x
x x x x
Table 1
Segment
Boolean Equation (Boolean Algebra) a
b
c
d
e
f
g
Table 2 Decoder Output
Boolean Equation
A
B
C
D
Table 3 Encoder Segment
Boolean Equation (Logic Converter) a
b
c
d
e
f
g
Table 4 Decoder
SCHEMATIC DIAGRAM Draw the complete schematic diagram here: -10 SPDT connected either to supply voltage Vcc (as logic 1 input) or ground (as logic 0 input) -Encoder circuit: Output A, B, C and D -Decoder circuit: segment a, b, c, d, e, f and g diagram -Output display: 7-segment display or 7-LEDs or 7-logic probes
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
3 MULTIPLEXER AND MAGNITUDE COMPARATOR
INFORMATION In this experiment new devices such as Multiplexer and Magnitude Comparator are introduced. A multiplexer or mux is a device that performs multiplexing, it selects one of many analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select lines, which are used to se lect which input line to send to the output. An electronic multiplexer makes it possi ble for several signals to share one device or resource, for example one A/D converter or one communication line, instead of having one device per input signal. A magnitude comparator is a hardware electronic device that takes two numbers as input in binary form and determines whether one number is greater than, less than or equal to the other number. Comparators are used in a central processing units (CPU) and microcontrollers. Examples of digital comparator include the CMOS 4063 and 4585 and the TTL 7485 and 74682-'89. OBJECTIVES . To learn about the use of a Multiplexer and a Magnitude Comparator in a circuit. . To compare different inputs using the magnitude comparator together with LEDs as indicators. . To display numbers from 0-9 with the common cathode seven segment display and switch whichever number is desired to be displayed by altering the switch that represents to Encoder A and encoder B.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Find models of the following components: Encoder Decoder Multiplexer Magnitude Comparator Seven segment display (Common Cathode) 2. Browse the internet for more information about each component and for the datasheets of specific models whose product design suits the virtual components of Multisim 11. 3. Study the datasheets to know more about the components and the factors that shall affect the circuit as a whole.
Lab Proper Part 1: Multiplexer 1. Setup the two different encoders according to how it works properly during pre lab activity. There should be nine switches in the input of encoder A and nine switches in encoder B. 2. The outputs of the encoder A will be connected in the inputs A of the multiplexer. Connect according to which are the MSB and LSB. Also, the outputs of the encoder B will be connected in the inputs B of multiplexer. 3. Setup the decoder as planned in the pre lab activity. Now, connect the for output pins of the multiplexer to the input pins of the decoder. Also, connect according to MSB and LSB. 4. Use a SPDT switch in the selector pins. If the selector has two pins for selector, connect the two pins in the two throws of the switch. Connect a Vcc in the other end of the switch. The selection of the pin will be based on the pin that is supplied by the voltage. 5. Turn on the Vcc s and select the inputs according to Table 1. Record the corresponding output display.
Part 2: Magnitude Comparator 1. The setup used in the part 1 of the activity will be used for this part of the activity. 2. Connect the A>B and AB in series with the 470O resistor and a red LED. The output of A=B is connected with 470O and green LED. And lastly, the output of A
FOLLOW UP ACTIVITY Using the same concept, make a circuit that shall display 2 separate digits using 2 seven-segment display but this time the common anode seven-segment display must be used. On the circuit itself, there will be lots of changes on th e way it was interconnected because different pins would now be used. Redesigning the circuit is now a must and the components will then be changed. Again, research for the datasheet of the new components and be familiar with its pins. Construct the circuit on the Multisim 11 and make some test to confirm its validity. Some of the inverters which were used in the previous circuit may no longer be of any use now while some would be just transferred at the different parts of the circuit. RESULTS TABLES: ENCODERS (input) SELECTORS (display output) Encode A Encoder B If selector A If selector B 0 9
1 8
2 7
3 6
4 5
5 4
6 3
7 2
8 1
9 0
0 0
2
2
Table 1
ENCODERS (input) Output (Color of LED that is ON) Encode A Encoder B 0 9
1 8
2 7
3 6
4 5
5 4
6 3
7 2
8 1
9 0
0 0
2 2
Table 2
SCHEMATIC DIAGRAM Draw the complete schematic diagram here:
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
4 BCD ADDER
INFORMATION The binary coded decimal (BCD) adder circuit adds two BCD encoded operands and produces a BCD encoded sum and a carry out bit. It includes a bank of parallel full adder circuits as a first stage which generates an intermediate sum vector and an intermediate carry vector from the sum of the operands and a pre-correction factor. A second stage of the BCD adder circuit includes carry look-ahead adder circuitry receiving as inputs the intermediate sum vector and the intermediate carry vector and producing a propagate vector and a final carry vector. The third stage of the BCD adder circuit conditionally modifies the propagate vector to form the BCD encoded sum according to bits of the intermediate carry vector and the final carry vector as inputs. Binary coded decimal numbers are used to represent decimal numbers in a form readily understood by both man (decimal) and computer (binary). There are sixteen possible bit combinations using four binary bits, but only ten are valid BCD digits. Therefore, when two BCD digits are added and the sum digit exceeds nine, that sum digit must be adjusted to a valid BCD digit. This is generally done by adding the constant 0110 2 (6 10) to the sum. Traditionally, BCD adder circuits have used logic to detect whether a BCD sum should be adjusted after the addition has been completed. For example, whenever the unadjusted sum of two BCD digits produced a carryout (i.e., when the sum exceeds fifteen), the sum was corrected by adding 0110 2. Also, an adjustment was needed whenever bit positions 8 and 4 of the BCD sum were both one's (values 12 10 -15 10) or when bit positions 8 and 2 were both one's (values 10 10 and 11 10).
OBJECTIVES . To add/subtract BCD numbers using the 4 bit FULL-ADDER and displaying the digits on Seven-Segment Two-Digit Display and the corresponding operations on Alpha-Numeric Display. . To apply the functions of logical gates in obtaining correct results in performing addition or subtraction. In the process of addition, the sum should be corrected by a correction factor. Also, it is required that the same circuit can be switched and can process subtraction. . To understand how the 4-bit full adder function and know how each pins are connected to other circuit parts in order to come up with the desired output.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Configure a common-cathode Alpha-Numeric Display such that the plus and minus signs shall be displayed one at a time. This later on will be used at the actual lab activity wherein the plus or minus sign should be displayed accordingly to what operation is desired to be perform by the circuit. This can be done through knowing what the functions are for each pins of the Alpha-Numeric Display.
2. Using a Seven-Segment One-Digit Display at common cathode configuration, display the equal sign. This will be used to specify the result of the 2 digits to be added or subtracted on the circuit. This display shall be placed before the answer when addition or subtraction was implemented.
3. Study the datasheet of the 4-bit adder that will be used.
Lab Proper 1. Construct a circuit that shall have 2 encoders and 2 decoders connected to separate common cathode Seven-Segment Displays. This shall serve as the way in which the numbers to be added or subtracted can be selected. 2. In making the diagram, choose suited Integrated Circuits that can accommodate the total number of inputs and outputs for each Encoder and Decoder. Look for the pin configuration of your chosen IC and connects pins in their proper places. 3. Test the diagram by switching on 1 switch from each of the two 8 item switch pack. The number chosen must be displayed on the Seven-Segment Display.
4. Search for a 2 identical 4 bit full adders. Connect this with one another and use some gates and switch that shall serve as the ON and OFF of addition and subtraction to facilitate the operation and conversions together with the correcting factors.
5. Combine the completed 4 bit full adder/subtractor with the encoders and decoders. 6. Insert the plus/minus/equal signs and arranged it in such a way that the displays shall resemble an equation for better appearance. 7. Test the circuit by selecting numbers to be added/subtracted then switch operations to addition/subtraction. Record the results in Table 1.
FOLLOW UP ACTIVITY In the Actual Lab part, the 4 bit adder used was in the form of Integrated Circuit. With this practice, it is easy to identify connections and how to place the IC properly in the circuit by just looking at its pin configuration. To further understand the concept of a 4 bit adder, it is suggested that the components inside the IC must be studied and how it works in the circuit in order to perfor m desired operations. In this part of the activity, construct a circuit consisted by logic gates to form a 4 bit adder. Look for a schematic diagram of a 4 bit adder then simplify the figure with the use of Boolean Algebra to lessen the number of gates. The same output as to what was done in the Actual Lab is expected.
RESULTS TABLE 1: First Number Operation Second Number Result 5 + 4
7 + 6
8 + 7
8 + 8
9 + 9
9 0
8 1
7 2
6 3
5 4
SCHEMATIC DIAGRAM Draw the complete schematic diagram here:
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
5 LATCH AS A MEMORY DEVICE
INFORMATION Latches are circuits used to store information. They may be in the form of Integrated Circuits containing several combinations of logical gates whose inputs/outputs are corresponded by the pins on the external part of the IC. SR latch is a sequential circuit with two inputs called SET and RESET, which make the SR latch store a logic 0 (reset) or 1 (set) until actively change . The enable input on a gated SR latch provides a way to latch the Q and not-Q outputs without regard to the status of S or R. The D-latch is rarely related to gated-SR latch. Another character of Dlatch is that it can be constructed similarly to SR latch. The inverter added to R input prevents the Restricted Combination (RC) State. The D-latch is also known as transparent latch, data latch, or simply gated latch. It has a data input and an enable signal. It had been called transparent due to the fact that, when the ena ble input is on (1), the signal would propagate directly through the circuit, from t he input D to the output Q. Whatever you had input will be automatically your outpu t. D:\Switay\Second Sem 2010-2011\Logic 1\latch5.bmp D:\Switay\Second Sem 2010-2011\Logic 1\lab7.bmp D:\Switay\Second Sem 2010-2011\Logic 1\lab7.bmp
OBJECTIVES . To construct a circuit using SR or D Latches which can store encoded inputs and decoded outputs. . To make use of the different logical gates in order to obtain desired result. . To apply encoder, decoder, multiplexers, and BCD adder/subtractor.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Look for latch models (SR or D Latch) to be use in the simulation and study each of their datasheets. 2. Study the BCD Adder/Subtractor circuit done on Laboratory Activity 4. 3. Review the function of the multiplexer used on Laboratory Activity 3.
Lab Proper 1. Using the searched properties of the latch, connect the necessary voltages like ground and Vcc. 2. Connect a Vcc and resistor in the ten push buttons representing numbers 0 9. Connect the encoder. 3. Connect the first four latches to the output of the encoder and connect it to a decoder and hex display, this is just the first digit. Add another four latches to store the first digit and reset the first set of latches, so that the second digit can be stored in it. Thus, the ten s digit is stored in the second set of latches and the one s digit is stored in the first set of latches. 4. Try simulating it to assure correct junctions, components, sources, etc. If the circuit is not working, check the connections or any possible errors. 5. If working, connect another four latches to both one s and tens digit to store the first number encoded. And store the second number to be added or subtracted to the first two sets of latches.
6. Repeat step 4, but if working connect four-bit adder and multiplexer to generate the desired operation. Multiplexer is used so that there will only be three hex displays which will show the input numbers and the sum or difference. Four-bit adder is used to perform addition and subtraction, correcting factor is necessary. 7. To check, switch the push button representing a number. Input a twodigit number, choose whether to add or subtract then input the next number. The result should output the right sum or difference of the inputted numbers. Record the results in Table 1. FOLLOW UP ACTIVITY In this activity, 2-digit numbers were stored, added and maximum digit combination of 99+99=198 as the result. As a follow-up activity, reconfigure the circuit in such operations done in the previous circuit can be performed addition/subtraction of another digit. This time 3-digit
subtracted with a a way that same with the numbers must be stored,
added and subtracted. The maximum result should be 999 + 999 = 1998 for addition.
RESULTS TABLE 1: First Number Operation Second Number Result 64 + 28
75 + 39
35 + 7
9 + 8
5 + 4
91 42
86 28
57 9
18 3
5 4
SCHEMATIC DIAGRAM Draw the complete schematic diagram here:
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
6 COUNTERS USING FLIP-FLOPS
INFORMATION Flip flops are commonly associated with clocks. Flip flops are being triggered by the edge of the clock. Since there are only two edges in a digital/square waveform, flip flops can either be triggered when there is a risi ng edge or falling edge. Flip-flop is a circuit that has two stable states and can be used to store stat e information. A flip-flop circuit can be constructed from two NAND gates or two N OR gates. It has three types, namely, D Flip-Flop (DFF), T-Flip Flop (TFF), and the JK-Flip Flop (JKFF). The D-Flip Flop (DFF) is the most common flip-flop. It is better known as data or delay flip-flop as its output Q looks like a delay of input D. The Q output takes on the state of the D input at the moment of a positive edge at the clock pin or negative edge if the clock input is active low. For the T-Flip Flop (TFF), if the T input is high, the T flip-flop changes state or toggles whenever the clock input is strobe. If the T input is low, the flip-f lop holds the previous value. A JK Flip-Flop (JKFF) is a refinement of the SR flip-flop in that the indeterminate state of the SR type is defined in the JK type. Inputs J and K behave like inputs S and R to set and clear the flip-flop. Counters are the main application of these latches. These counters can either be up counting or down counting. Because of the clock (timed by the user) , the circuit can be designed in anyway depending on the desired counting of the user. In digital logic and computing, a counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal. In electronics, counters can be implemented quite easily using registertype circuits such as the flip-flop, and a wide variety of classifications exist : . Asynchronous (ripple) counter changing state bits are used as clocks to subsequent state flip-flops
. Synchronous counter all state bits change under control of a single clock . Decade counter counts through ten states per stage . Up/down counter counts both up and down, under command of a control input . Ring counter formed by a shift register with feedback connection in a ring . Johnson counter a twisted ring counter . Cascaded counter Usually, counter circuits are digital in nature, and count in natural binary. Many types of counter circuits are available as digital building blocks, for exa mple a number of chips in the 4000 series implement different counters. Occasionally there are advantages to using a counting sequence other than the natural binary sequence, such as the binary coded decimal counter, a linear feedback shift register counter, or a Gray-code counter. Counters are useful for digital clocks and timers, and in oven timers, VCR clocks, etc. OBJECTIVES . To know the concepts and operations of flip flops. . To know the effect of clock in the flip flops. . To use flip flops as counter. . To design a different types of counters: Down Counter (DFF, TFF, JKFF); Up Counter (DFF, TFF, JKFF); Up Down Counter (DFF, TFF, JKFF); Bidirectional Counter with parallel loading (DFF, TFF, JKFF).
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. a. b. c.
Study the characteristics of each of the following Flip-Flops: D-Flip Flop T-Flip Flop JK-Flip Flop
2. Construct an excitation table for an Up-Counter that can display numbers 0 to 9. Complete the excitation table for each of the 3 Flip Flops. Record the results in Table 1, 2 and 3. Make also an excitation table for DFF down counter (Table 4), and DFF bidirectional counter (Table 5). 3. From the excitation table, use Karnaugh Mapping to obtain the equations in their simplest forms for each respective set of inputs. Use dont care (x) for unused states.
Lab Proper 1. Using the obtained equations from the Pre-lab activity, construct individual circuits for each of the Up-Counters (DFF, TFF, and JKFF), DFF down counter, and DFF bidirectional counter. FOLLOW UP ACTIVITY Construct a two-digit down counter using the D-Flip Flops, T-Flip-Flops, and JK-Flip-Flops. With these two-digit down counters, the minimum requirement is that the maximum number to be displayed on each must be the number 15 and minimum must be 00.
RESULTS TABLE: Present state Q3 Q2 Q1 Q0 D3 D2 D1 D0 Next state 0000 0 0 0 1 0001 0001 0 0 1 0 0010 0010 0 0 1 1 0011 0011
0100 0100
0101 0101
0110 0110
0111 0111
1000 1000
1001 1001
0000 D3 =
D2 =
D1 =
D0 =
Table 1 Up-Counter (0-9) DFF
TABLE: Present state Q3 Q2 Q1 Q0 T3 T2 T1 T0 Next state 0000 0 0 0 1 0001 0001 0 0 1 1 0010 0010 0 0 0 1 0011 0011
0100 0100
0101 0101
0110 0110
0111 0111
1000 1000
1001 1001
0000 T3 =
T2 =
T1 =
T1 =
Table 2 Up-Counter (0-9) TFF
TABLE: Present state Q3 Q2 Q1 Q0 J3 K3 J2 K2 J1 K1 J0 K0 Next state 0000 0 X 0 X 0 X 1 X 0001 0001 0 X 0 X 1 X
X 1 0010 0010 0 X 0 X X 0 1 X 0011 0011
0100 0100
0101 0101
0110 0110
0111 0111
1000 1000
1001 1001
0000 J3 =
K3 =
J2 =
K2 =
J1 =
K1 =
J0 =
K0 =
Table 3 Up-Counter (0-9) JKFF
TABLE: Present state Q3 Q2 Q1 Q0 D3 D2 D1 D0 Next state 0000
1001 0001
0000 0010
0001 0011
0010 0100
0011 0101
0100 0110
0101 0111
0110 1000
0111 1001
1000 D3 =
D2 =
D1 =
D0 =
Table 4 Down-Counter (9-0) DFF
TABLE: S Q3 Q2 Q1 Q0 D3 D2 D1 D0 NEXT STATE 10000
0001 10001
0010 10010
0011 10011
0100 10100
0101 10101
0110 10110
0111 10111
1000 11000
1001 11001
0000 00000
1001 00001
0000 00010
0001 00011
0010 00100
0011 00101
0100 00110
0101 00111
0110 01000
0111 01001
1000
(S = 0 Down Counter; S = 1 Up Counter) Table 5 Bidirectional-Counter (0-9) DFF
SCHEMATIC DIAGRAM Draw the complete schematic diagram here: . . . . .
DFF Up-Counter TFF Up-Counter JKFF Up-Counter DFF down counter DFF bidirectional counter.
ANALYSIS / OBSERVATION:
CONCLUSION:
Activity
7 SHIFT REGISTERS
INFORMATION Shift registers are kind of sequential logic circuits that were mainly used to store digital data. The main components of a shift register were flip flops. The se were used to store a bit in a flip flop. The circuit was configured in such a wa y that the flip flops are like in series connection. The concept of connecting the flip flops in series was to transfer the data from the flip flop to the other flip fl op. These shift registers were applied to store data and move data. The movement of data was dependent to the common clock connected to the flip flops. OBJECTIVES . To understand the function of register. . To construct a Shift Right Register (SHR) and a Shift Left Register (SHL) using D Flip-Flop. . To construct a Universal Shift Register using the following Flip-Flops: a. D Flip-Flop b. T Flip-Flop c. JK Flip-Flop . To construct a Johnson Counter with Decoded 8-LEDs Running Display using D Flip-Flop.
MATERIALS/EQUIPMENT . PC/laptop with pre-installed Multisim 11
PROCEDURE Prelab 1. Study the behavior of the Shift Right Register and Shift Left Register and how it can be implemented using the D Flip-Flop. 2. Research on how the Universal Shift Register works. 3. Look for some schematic diagrams that shall present how the different types of Flip-Flops are used together with gates and other components to construct a Universal Shift Register, specifically, how it is being implemented using the DFF, TFF and the JKFF.
A B Function 0 0 No change/ stop 0 1 SHR 1 0 SHL 1 1 Parallel Load
4. Find some resources about the 5. Examine how to make a Johnson Decoded 8-LEDs Running Display. 6. Considering the properties of Johnson Counter with the Decoded
Johnson Counter. Counter that shall have with it the D Flip-Flop, make a diagram of the 8-LEDs Running Display.
Lab Proper 1. Construct a Shift Right Register using the D Flip Flop. Interconnect gates and some components to implement the Shift Right Register. 2. Use different colored probes as indicators. 3. Make a Shift Left Register using the same Flip-Flop as was used in the Shift Right Register and different colored probes as indicators. 4. Use the square waveform as the clock voltage. 5. Create a Universal Shift Register, first using the D Flip-Flop. 6. As what was studied on the Pre Lab Activity, carefully connect the pins, gates, switches, and other components as required. 7. With the same procedure as the Universal Shift Register using the DFF, implement the Universal Shift Register first using the TFF then the JKFF with the additional considerations on each characteristic. 8. Based on what was researched on the Pre Lab activity about the Johnson Counter with Decoded 8-LEDs Running Display, make a simulation that shall implement it and use different colored LEDs as indicators.
FOLLOW UP ACTIVITY 1. Design a Shift Right Register and a Shift Left Register using the T FlipFlop and the JK Flip-Flop. 2. Formulate equations that can satisfy the requirements of the Toggle FlipFlop and the JK Flip-Flop separately. 3. With these equations, simulate the diagram and see if the results appear to be true with what the Shift Right Register and Shift Left Register were supposed to operate. 4. Simulate a Johnson Counter with 8-LEDs Running Display using the T Flip-Flop and the JK Flip-Flop. 5. Use different colored indicators for the running display for more distinguishable result. 6. Also, perform the Ring-Counter using the D Flip-Flop, T Flip-Flop and the JK Flip-Flop. Use probes as indicators.
RESULTS SCHEMATIC DIAGRAM Draw the complete schematic diagram here: - DFF SHR - DFF SHL - DFF Universal Shift Register - TFF Universal Shift Register - JKFF Universal Shift Register - Johnson Counter with 8-LEDs Running Display
ANALYSIS / OBSERVATION:
CONCLUSION:
