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Unformatted text preview: Mallard ECE 290: Computer Engineering I  Spring 2007  Graded WebQuiz: Design a 1... Page 1 of 3 Graded
Graded WebQuiz: Design a 110 Sequence
Recognizer, Part I
You have submitted this WebQuiz 3 times (including this time).
You may submit this WebQuiz a total of 10 times and receive full credit.
In this quiz you will derive the next state table for a 110 sequence recognizer. You will then implement
this circuit using SR or JK flipflops. Question
Question #1
Given below is the state diagram of a sequential network with one input x and one ouput z which
recognizes the sequence 110. State A is the start state, and the other states B and C are traversed in
order when the input is 110. Example:
x = 1 1 0 0 1 1 0 1 0 1 1 1 1 0 1 0 0 1 0 ...
z = 0 0 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 ... For each state A, B, C give the "meaning" of that state by entering a 01 sequence into the blank. For
the start state enter "none" or "", corresponding to having read no bits that could be the start of a 110
sequence.
State
State Meaning
Meaning A has just been read B 1 has just been read C 11 has just been read Complete the following nextstate table.
Current
Current State Input x Next state Output z
A 0 A 0 https://mallard.cites.uiuc.edu/ECE290/webgrade.cgi?SessionID=mding3_1070311_13325... 3/11/2007 Mallard ECE 290: Computer Engineering I  Spring 2007  Graded WebQuiz: Design a 1... A 1 B 0 B 0 A 0 B 1 C 0 C 0 A 1 C 1 C Page 2 of 3 0 You received a raw score of 100% on this question. Question
Question #2
In this question you will use SR flipflops to implement a circuit that recognizes 110.
flipRefer back to the 110 recognizer from Question #1. Use the following Q1Q2 state assignment:
A = 00, B = 10, C = 11
Complete the state table given below, providing the next state Q1+Q2+, the output z, and the required
flipflop excitations S1,R1 and S2,R2. Use don't cares wherever possible.
Current
Current State Input Next State Output FlipFlipFlop Inputs Q1
Q1 Q2 x Q1+ Q2+ 0 0 0 0 0 0 0 X 0 X 0 0 1 1 0 0 1 0 0 X 0 1 0 X X X X X X X 0 1 1 X X X X X X X 1 0 0 0 0 0 0 1 0 X 1 0 1 1 1 0 X 0 1 0 1 1 0 0 0 1 0 1 0 1 1 1 1 1 1 0 X 0 X 0 z S1 R1 S2 R2 Your points: 100.00
Give boolean expressions for the output z and the flipflop inputs S1, R1, S2, and R2.
Q2x'
z = Q2x'
S1 xQ2'
S1 = xQ2' https://mallard.cites.uiuc.edu/ECE290/webgrade.cgi?SessionID=mding3_1070311_13325... 3/11/2007 Mallard ECE 290: Computer Engineering I  Spring 2007  Graded WebQuiz: Design a 1... Page 3 of 3 R1 Q1x'
R1 = Q1x'
S2 xQ1
S2 = xQ1
R2 x
R2 = x''
Item 1: You have filled in all 56 entries in the table correctly.
You received a raw score of 100% on this question. WebQuiz
WebQuiz Grade Summary
Raw score
Adjusted score
Minimum passing score
Grade for this submission
Cumulative
Cumulative Grade 100.00%
100.00%
60.00%
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Course Content Copyright?19952007 Donna J. Brown. All rights reserved. https://mallard.cites.uiuc.edu/ECE290/webgrade.cgi?SessionID=mding3_1070311_13325... 3/11/2007 ...
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