Recap D flip-flop based counter Flip-flop transition table Flip-flop input table Karnaugh maps Logical expressions for flip-flop inputs Sequential circuit Implementation
Digital Logic & Design Dr. Waseem Ikram Lecture 33
Three possible state assignments for states a, b, c, d and f 000 001 b 010 c 011 d 100 f 110
Next State flip-flop input table for first State Assignment Present State Next State D flip-flop Inputs Output X=0 X=1 000 100 001 1 010 011
X Q x D + = 1 2 + = Q X D Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 1 2 + = 1 2 + = Q X D Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 1 x
X Q D 1 2 + = Q2Q1/Q0X 00 01 11 10 1 x
Next State flip-flop input table for second State Assignment Present State Next State D flip-flop Inputs Output X=0 X=1 001 110 010 1 011 100
X Q D + = X Q x D + = Q2Q1/Q0X 00 01 11 10 x 1 Q2Q1/Q0X 00 01 11 10 x + = X Q D 1 2 + = Q2Q1/Q0X 00 01 11 10 x 1 Q2Q1/Q0X 00 01 11 10 x 1
X Q D 1 2 + = Q2Q1/Q0X 00 01 11 10 x 1
Next State flip-flop input table for third State Assignment Present State Next State D flip-flop Inputs Output X=0 X=1 000 110 001 1 011 010
D = Q x + Q X + Q Q 1 1 D = Q Q x + Q Q X Q2Q1/Q0X 00 01 11 10 1 x 1 1 1 Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 1 x
Q2Q1/Q0X 00 01 11 10 x 1
Next State flip-flop input table for third State Assignment Present State Next State D flip-flop Inputs Output X=0 X=1 000 110 001 1 011 010
D = Q Q x + Q Q X D = Q x + Q X + Q Q 1 1 1 Q2Q1/Q0X 00 01 11 10 1 x 1 1 1 Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 1 x
D = Q Q Q x + Q X + Q Q + Q X 2 1 2 1 1 Q2Q1/Q0X 00 01 11 10 1 x
Karnaugh Map for J2 and K2 inputs Q2Q1/Q0 1 00 x 01 11 10 Q2Q1/Q0 1 00 x 01 11 10 1 2 = Q J 1 2 = Q K
Karnaugh Map for J0 and K0 inputs Q2Q1/Q0 1 00 x 01 11 10 Q2Q1/Q0 1 00 x 01 11 10
Implementation of the Moore Machine
Timing diagram of the Moore Machine
Karnaugh Map for J1 and K1 inputs Q2Q1/Q0 1 00 x 01 11 10 Q2Q1/Q0 1 00 x 01 11 10 1 = J 1 = Q K
State diagram of a Moore Machine
Next-State table of the Moore Machine Present State Next State Q2 Q1 Q0 1
J-K flip-flop input table for the Moore Machine Present State Next State J-K flip-flop inputs Q2 Q1 Q0 J2 K2 J1 K1 J0 K0 1 x
State diagram of a Mealy Machine
Next-State table of a Mealy Machine Present State Next State Output X=0 X=1 a b 011 111 c 001 d 010 e 100 f 110
State Assignments for the Mealy Machine Present State Next State X=0 X=1 000 001 011 010 110 100
J-K flip-flop input table for the Moore Machine (X=0) Present State Next State X=0 J-K flip-flop inputs Output Q2 Q1 Q0 J2 K2 J1 K1 J0 K0 O2 O1 O0 x 1
J-K flip-flop input table for the Moore Machine (X=1) Present State Next State X=1 J-K flip-flop inputs Output Q2 Q1 Q0 J2 K2 J1 K1 J0 K0 O2 O1 O0 1 x
Karnaugh Map for J0 and K0 inputs Q2Q1/Q0 1 00 x 01 11 10 Q2Q1/Q0 1 00 x 01 11 10
Karnaugh Map for J2 and K2 inputs Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 x 1 X Q J 1 2 = X Q K 1 2 =
Karnaugh Map for J1 and K1 inputs Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 x 1 X Q J 1 = 2 1 + = Q K
Karnaugh Map for J0 and K0 inputs Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 x 1 X Q J 1 2 = X Q K 1 =
Karnaugh Map for J1 and K1 inputs Q2Q1/Q0X 00 01 11 10 x 1 Q2Q1/Q0X 00 01 11 10 1 x J = Q X K = Q X 1 1 2
X Q O + = X Q O 1 2 + = Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 1 2 + = X Q O 1 2 + = Q2Q1/Q0X 00 01 11 10 1 x Q2Q1/Q0X 00 01 11 10 1 x
Karnaugh Map for O2, O1 and O0 outputs Q2Q1/Q0X 00 01 11 10 1 x X Q O 1 2 + =
Karnaugh Map for J1 and K1 inputs Q2Q1/Q0 1 00 x 01 11 10 Q2Q1/Q0 1 00 x 01 11 10
Implementation of the Mealy Machine
Timing diagram of the Mealy Machine
Implementation of the Moore Machine
Timing diagram of the Moore Machine
Recap Design of Up/Down Counter State Diagram Next-State Table Flip-flop transition table Flip-flop input table Karnaugh maps Logical expressions for flip-flop inputs Sequential circuit Implementation
Recap State Reduction State Diagram Input/Output sequence using original state diagram Next-State table reduction Reduced State Diagram Input/Output sequence using reduced state diagram
State Assignment State Assignment Table (tab 1) Flip-flop input table & K map for 1st assignment (tab 2) Flip-flop input table & K map for 1st assignment (tab 3) Flip-flop input table & K map for 1st assignment (tab 4)
Moore Machine State Diagram (fig 1) Next-State Table (tab 5) J-K flip-flop Input Table (tab 6) Karnaugh Maps (tab 7a, 7b, 7c) Implementation (fig 2a) Timing diagram (fig 2b)
Mealy Machine State Diagram (fig 3) Next-State Table (tab 8) State Assignment (tab 9) J-K flip-flop Input Table (tab 10a, 10b) Karnaugh Maps (tab 11a, 11b, 11c, 11d) Implementation (fig 4a) Timing diagram (fig 4b) Output
Shift Registers Serial In/Shift Right/Serial Out (fig 1) Serial In/Shift Left/Serial Out (fig 2) D flip-flop based Serial Shift Reg. (fig 3a) Timing diagram (fig 3b) Universal Serial register (fig 4a) Timing diagram (fig 4b)
Shift Registers Serial In/Parallel Out (fig 5) Serial In/Parallel Out 74HC164 (fig 6a) Timing diagram (fig 6b) Parallel In/Serial Out (fig 7) Circuit diagram Parallel In/Serial Out (fig 8) 74HC165 (fig 9)