- Draw the Present/Next State Table
- Write the Excitation-Input Equations
Di = Σ(PS.external input for set) + Σ(PS.external input for hold 1 ) - Draw the schematics
Set-Clear Method for obtaining T Excitation-Input Equations
The following table will be used to write T excitation equations directly from a state diagram, ASM
chart, or a timing diagram.
Present State
(PS/NS)
Yi Yi+
Ti
Comment
User for 1s
(Set-Hold 1)
Use for 0s
(Clear-Hold 0)
0 0
0 1
1 0
1 1
0
1
1
0
Hold 0 transition
Set transition
Clear transition
Hold 1 transition
Ti
Ti
Ti’
Ti’
The “Set – Clear Method” can be used to obtain the T excitation equations for the 1s of each
state variable (flip flop outputs)
Ti = ∑ (PS .external input conditions for set) + ∑ (PS .external input conditions for clear)
for i = 1,2,3,...
Note: This method solves for the 1’s of the function.
We could also apply the “Hold 0 - Hold 1 Method” to obtain the T excitation equations for the
0s of each state variable (flip flop outputs)