EECE 320 Lecture 22, Fall 2011

EECE 320 L21B: Combinational Logic design Practices 1 Chehab, AUB, 2003 EECE 320 Digital Systems Design Lecture 22: Sequential Logic Design Principles Ali Chehab EECE 320 L21B: Combinational Logic design Practices 2 Chehab, AUB, 2003 Analysis of State Machines with D Flip Flops - Example EN S 0 1 A A,0 B,0 B B,0 C,0 C C,0 D,0 D D,0 A,1 S*, MAX EECE 320 L21B: Combinational Logic design Practices 3 Chehab, AUB, 2003 Analysis of State Machines with D Flip Flops – Example 2 EECE 320 L21B: Combinational Logic design Practices 4 Chehab, AUB, 2003 Analysis of State Machines with D Flip Flops – Example 2  Excitation Equations  D0 = Q1’.X + Q0.X’ + Q2  D1 = Q2’.Q0.X + Q1.X’ + Q2.Q1  D2 = Q2.Q0’ + Q0’.X’.Y  Transition Equations  Q0* = Q1’.X + Q0.X’ + Q2  Q1* = Q2’.Q0.X + Q1.X’ + Q2.Q1  Q2* = Q2.Q0’ + Q0’.X’.Y  Output Equations  Z1 = Q2 + Q1’ + Q0’  Z2 = Q2.Q1 + Q2.Q0’ EECE 320 L21B: Combinational Logic design Practices 5 Chehab, AUB, 2003 Analysis of State Machines with D Flip Flops – Example 2 Transition/Output Table State/Output Table EECE 320 L21B: Combinational Logic design Practices 6 Chehab, AUB, 2003 Analysis of State Machines with D Flip Flops – Example 2 Transition expressions on arcs must be mutually exclusive and all inclusive EECE 320 L21B: Combinational Logic design Practices 7 Chehab, AUB, 2003 Analysis of State Machines with J-K Flip Flops - Example EECE 320 L21B: Combinational Logic design Practices 8 Chehab, AUB, 2003 Analysis of State Machines with J-K Flip Flops - Example  Excitation equations  J0 = X.Y’ K0 = X.Y’ + Y.Q1  J1 = X.Q0 + Y K1 = Y.Q0’ + X.Y’.Q0  J-K characteristic equation  Q* = J.Q’ + K’Q  Transition eqautions  Q0* = J0.Q0’+K0’.Q0  Q0* = X.Y’Q0’ + (X.Y’ + Y.Q1)’.Q0  Q0* = X.Y’Q0’ + X’.Y’.Q0 + X’.Q1’.Q0 + Y.Q1’Q0  Q1* = X.Q1’.Q0 + Y.Q1’ + X’.Y’.Q1 + Y’.Q1.Q0’ + X’.Q1.Q0 + Y.Q1.Q0  Output equation  Z = X.Q1.Q0 + Y.Q1’.Q0’ EECE 320 L21B: Combinational Logic design Practices 9 Chehab, AUB, 2003 Analysis of State Machines with J-K Flip Flops - Example EECE 320 L21B: Combinational Logic design Practices 10 Chehab, AUB, 2003 Analysis of State Machines with J-K Flip Flops - Example EECE 320 L21B: Combinational Logic design Practices 11 Chehab, AUB, 2003 Next Lecture and Reminders  Next lecture  Reminders