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Published byBarrie Flowers Modified over 9 years ago
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Sequential Design Motivation Sequential processing often more tractable than parallel Example Sequential processing sometimes only method that works Example (generalization of parity)
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Sequential Design Finite State Machines Elements states transitions output(s) Example
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Sequential Design Finite State Machines Sequence recognition 1) Create machine to recognize sequence 2) Fill in other states Example (“abac”) Note: Must handle cases whereby non-initial substring is target sequence
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Sequential Design Mealy and Moore Machines Moore output function of current state only Mealy output function of current state and current inputs
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Sequential Design i) Derive the transition equations from the next state logic iii) Construct a transition/output table from the equations produced in i) and ii) ii) Derive the output equation from the output logic iv) Construct a state/output table by labeling the states in iii) v) Derive a DFSM from the table in iv) vi) State in ordinary language what the machine is doing
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Sequential Design Sequential Machine Analysis Example
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Sequential Design Sequential Machine Analysis Example i) Derivation of transition equations Q0 + = Q0I0'I1' + Q0Q1'I0' + Q0Q1'I1' + Q0'Q1I1 + Q0'Q1I0 + Q0'I0I1 Q1 + = Q1I0'I1' + Q1'I0'I1 + Q1I0I1 + Q1'I0I1'
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Sequential Design Sequential Machine Analysis Example ii) Derivation of output equation OUT = Q0'Q1'
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Sequential Design Sequential Machine Analysis Example iii) Construction of the transition/output table Q0 + = Q0I0'I1' + Q0Q1'I0' + Q0Q1'I1' + Q0'Q1I1 + Q0'Q1I0 + Q0'I0I1 Q1 + = Q1I0'I1' + Q1'I0'I1 + Q1I0I1 + Q1'I0I1' I0I1I0I1 Q0Q1Q0Q1 00011011OUT 00 01 101 01 10 110 10 11 000 11 00 010 Q0+Q1+Q0+Q1+
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Sequential Design Sequential Machine Analysis Example iv) Construction of the state/output table A = 00 B = 01 C = 10 D = 11 I0I1I0I1 Q0Q1Q0Q1 00011011OUT AABBC1 BBCCD0 CCDDA0 DDAAB0 Q0+Q1+Q0+Q1+
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Sequential Design Sequential Machine Analysis Example v) Derivation of the finite state machine I0I1I0I1 Q0Q1Q0Q1 00011011OUT AABBC1 BBCCD0 CCDDA0 DDAAB0 Q0+Q1+Q0+Q1+
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Sequential Design Sequential Machine Analysis Example vi) Ordinary language description?
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Sequential Design Sequential Machine Synthesis i) Finite state diagram construction ii) State/output table construction iii) State-variable assignment iv) Substitution of state-assignments into the state/output table v) Construct an excitation table vii) Derive output equations from the transition/output table vi) Derive excitation equations from this table viii) Draw a circuit diagram that realizes the excitation and output ix) Verification
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Sequential Design Sequential Machine Synthesis Example 1 (parity) i) State diagram construction
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Sequential Design Sequential Machine Synthesis Example 1 (parity) ii) Construction of the state/output table I Q0Q0 01OUT even odd0 even1 Q0+Q0+
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Sequential Design Sequential Machine Synthesis Example 1 (parity) iii) State variable assignment 0 = even 1 = odd I Q0Q0 01OUT even odd0 even1 Q0+Q0+
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Sequential Design Sequential Machine Synthesis Example 1 (parity) iv) Transition/output table construction I Q0Q0 01OUT 0010 1101 Q0+Q0+
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Sequential Design Sequential Machine Synthesis Example 1 (parity) v) Excitation/output table construction I Q0Q0 01OUT 0010 1101 D0D0
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Sequential Design Sequential Machine Synthesis Example 1 (parity) vi) Excitation equation derivation I Q0Q0 01OUT 0010 1101 D0D0 D0 = Q0I' + Q0'I
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Sequential Design Sequential Machine Synthesis Example 1 (parity) vii) Output equation derivation I Q0Q0 01OUT 0010 1101 D0D0 OUT = Q0
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Sequential Design Sequential Machine Synthesis Example 1 (parity) viii) Circuit realization OUT = Q0 D0 = Q0I' + Q0'I
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Sequential Design Sequential Machine Synthesis Example 1 (parity) ix) Verification I01100111010 Q 01000101100 OUT 01000101100
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Sequential Design Sequential Machine Synthesis Example 2 (sequence recognition) i) Convert DFSM into binary
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Sequential Design Sequential Machine Synthesis Example 2 (sequence recognition) ii) Construct excitation/output table I0I1I0I1 Q0Q1Q2Q0Q1Q2 000110OUT 000001000 0 001 0100000 010011000 0 0110010101000 001000 1 D0D1D2D0D1D2
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Sequential Design Sequential Machine Synthesis Example 2 (sequence recognition) iii) Derive minimized excitation and output equations Note: x’s represent don’t care conditions
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Sequential Design Sequential Machine Synthesis Example 2 (sequence recognition) iv) All equations and circuit D0 = I0Q1Q2 D1 = I1Q2 + I0'I1'Q1Q2' D2 = I0'I1' OUT = Q0
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Sequential Design Sequential Machine Synthesis Example 2 (sequence recognition) v) Verification I0I0 000000100011 I1I1 101010001000 inputbababacabacc Q0Q0 000000100010 Q1Q1 001111001100 Q2Q2 010101010100 stateINITaababaababaabacaababaabacINIT OUT000000100010
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Sequential Design Sequential Machine Synthesis Example 3 (JK flip-flop design) Setting states QQ+Q+ JK 000x 011x 10x1 11x0 Q+ ≡ QN J + QK'
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Sequential Design Sequential Machine Synthesis Example 3 (JK flip-flop design) Mod 4 example I0I1I0I1 Q0Q1Q0Q1 00011011OUT 00 01 111 01 11 100 11 10 000 10 00 010 Q0+Q1+Q0+Q1+
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Sequential Design Sequential Machine Synthesis Example 3 (JK flip-flop design) Mod 4 example, excitation table I0I1I0I1 Q0Q1Q0Q1 00011011 000x,0x0x,1x 1x,1x 010x,x01x,x0 1x,x1 11 x0,x0x0,x1 x1,x1 10x0,0xx1,0x x1,1x J0 K0, J1 K1
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Sequential Design Sequential Machine Synthesis Example 3 (JK flip-flop design) Mod 4 example, excitation equations J0 = I0I1 + I1Q1 + I0Q1 K0 = I0I1 + I0Q1' + I1Q1' J1 = I0I1 + + I1Q0' + I0Q0' K1 = I0I1 + I1Q0 + I0Q0
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Sequential Design Sequential Machine Synthesis Example 3 (JK flip-flop design) Mod 4 example, realization
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Sequential Design Summary of Topics Finite state machines Sequential machine analysis Sequential machine synthesis D flip-flops JK flip-flops
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