??? 05/02/10 03:41 Read: times Msg Score: 0 +1 Informative -1 Answer is Wrong |
#175598 - A generic approach to dual edge detection Responding to: ???'s previous message |
Hi Arun,
Okay, first let me add my voice to the chorus/cacaphony of people saying, "Are You Nuts?!?!?!" That said, I have a generic approach to detecting both edges of a square wave pulse. I connect the pulse directly to one of two XOR gate inputs. I then connect the same signal to the other input of the same XOR gate, but this time through two inverters (NOT gates). At all times during the signal's period both XOR gate inputs will be either hi or lo, causing the output to be lo. However, for a very short time when the signal changes state, at both the PGT and NGT edges, the change at the second input will be delayed by the two inverters. During that short time the output will briefly go positive, and you have a dual edge detector. Joe |