I need help with the answer to a VHDL homework question

god

I need help with the answer to a VHDL homework question [Copy link]

Title: Design a state machine to detect when the input sequence "1110101101" starts from the left.
Questions: (1) Draw the state transition diagram of the state machine;
(2) Use the design method of the dual-process state machine to write its VHDL program.
Now I just want to know how to know how many states it has and what states it has? Ideas?

bagheera

How should I give it to you? Draw a picture or describe it to help you analyze it?

bagheera

Here is an example: Design a 110 alarm telephone switching device, that is, a sequence detector. When the continuous input signal is 110, the output of the circuit is 1, otherwise it is 0. Analysis: Don't be confused by 110. The key and difficulty of this problem lies in determining the state of the system. Preliminary assumptions show that there are the following states: 1: No valid signal is input. 2: A 1 is just input. (Note that this state is different from 1) 3: Two 1s are just input in succession. (Note that this state is different from 1 and 2) 4: Immediately after 3, a 0 is input. In fact, this is not an independent state different from the above 3. Because 110 is detected at this time and the corresponding response is made. In terms of state, it returns to the starting point (the first case), and the subsequent action of the circuit is exactly the same as if nothing happened. Yours is a "1110101101" telephone detector.

wealding

Related knowledge: Analysis and representation method of simple logic problems Karnaugh map characteristic equation driving equation Basic steps: 1. Logical abstraction to obtain a preliminary state transition diagram state diagram 2. Analyze the logic problem, determine the input and output variables, and the number of states 3. Define the meaning of the variables and encode the circuit state numbers 4. Draw a state transition diagram state diagram and list the state stable table state 5. State simplification: merge equivalent states (that is, under the same input conditions, enter the same state and get the same output state) 6. State allocation: that is, encoding: select the state according to a certain rule 7. Select the trigger type and then solve the state equation => driving equation => output equation flip-flops 8. Check the self-starting characteristics (if not, improve it) 9. Draw logic circuits

wealding

I suggest you take a good look at the design of synchronous sequential logic circuits.

god

Is it related to digital circuits? Why didn't I find it? I don't understand. I took the test today but didn't take this test. I still want to figure it out.

god

Can you send it to my email? Thanks, I still don't quite understand!
leijiarong520@yahoo.com.cn

wealding

Don’t you have a textbook?!

god

Yes, but I still don't understand.

wealding

Look carefully at the examples, it should be easy to understand. Alas! If you can't understand, then I can't help you!

god

Hehe, I respect my elder brother's teachings. Hehe, I still want to say thank you.