designdigital-logic
For a lab exercise I have to design a 2-input sequence and Im struggling with the state diagram, as It has 2 inputs, i've designed it with one input before. the sequence to be detected is 1032 which can be written as:
\$ A_{0} \text{ | 0 0 1 1} \$
\$ A_{1} \text{ | 1 0 1 0} \$
So how should I go about designing this state diagram?
Here's a hint: The states in your state machine are not associated with the binary codes representing the key inputs, they're associated with the number of correct numbers entered so far. You start out in an initial, or "reset" state, in which no valid keys have been entered so far, and then proceed to states representing 1 valid key entered, 2 valid keys entered, etc. until you get to the final state with 5 valid keys entered. In the last state, the output is 1; in all others it's 0.
In each state, if the next valid key is entered, you proceed to the next state; otherwise, you go back to the initial state.
S: initial node
A0..A3 represents the 0101 sequence
B0..B3 represents the 1100 sequence
The two digites after the state's name colon represent the output;
00 >> Z1=0, Z2=0
Drawn using graphviz
Best Answer
You need five states:
Some hints: Each state has four possible state transitions corresponding to inputs: 00 (0), 01 (2), 10 (3) and 11 (4). Most of these transitions will lead to state one. 01 input will always lead to state two.