Explanation of edges, circuit logic and the use of flip flop

[ilop]

help

hello i got stucked in several questions related to flip-flop and shift register, i hope there is someone who can answer these:

1.What is positive edge and negative edge in flip-flop circuit?
2. What are the differences between sequential circuit and combinational circuit?
3.What are the applications of flip-flop
4. How D-FF work in anti bouncing?


thank

 

[cedance]

Re: help

hi,

1) u have posted this before here. and got corres. satisfiable replies



2) pls choose a proper heading for ur question. that s also very importnt or ur message would go to trash!

3) reg. ur 4th one, How D-FF work in anti bouncing?
taken from page 506 and 507 of art of electronics. refer below. if A and B are same, RS becomes D FF.

/cedance

 

[VVV]

Re: help

1. Positive edge means "rising", that is the voltage rises from LOW to HIGH.
2. In a combinatorial crcuit the outputs are determined only by the combination of the inputs. In a sequential crcuit, the outputs depend on the inputs, but change only under the control of a clock signal.
3. Flip-flops can be used a 1-bit memory cells, in counters, frequency dividers, etc.
4. D flip-flops can be used to debounce a signal applied to their D input, if the clock input has a period longer than the bounce time. Since info is transferred from D to Q only on the edge of the clock, if the clock period is longer than the bounce time, the next active edge comes at a time when the input is stable, hence the output is noise-free (because the output essentially "ignores" the input between the clock actie edges).