Understanding the bit

[AntonioCS]

Hey! So I have been trying to pass chapter 3 but I am really failing.
I tried to implement the bit chip but was completely lost.

I had to see the implementation online, I am really trying to avoid looking the rest online, and still I didn't understand.

It used a DFF (which at least this one I understand) but after it used a MUX and an OR.
Ok I know that the DFF has a time delay so it's waiting for the tick/tock from the clock and since the MUX and OR chips don't have to wait for the clock they will click going and going they will be just generating garbage but how does the DFF use the out from Mux which also used the out from DFF??

I am really sorry if I am missing something obvious, I don't know how many times I have read chapter 3, I might have gotten something wrong in the other chapters.

Any other resource I can search? I have read the Lecture notes!

[cadet1620]

You are probably OK with chapters 1 and 2. The sequential circuits in chapter 3 make you think a bit differently.

Chapter 3 presents time as t-1 and t which means that one is thinking from the past into the present. Some people, myself included, prefer to think about time t and t+1, thinking from the present into the future, or "what comes next."

So the DFF in the bit is the value of the Bit right now. This implies that the DFF's out is the Bit's out.
The Bit's out is used to compute what the next value of the Bit should be (after the clock cycles once).

There must be some combinatorial logic on the input to the DFF that determines what the next value of the Bit should be. The Bit's next value is the same as its current value unless load is true, then the next value of Bit is the in value.


Send me email if you want more direct help with project 3.

--Mark