Advice about edge-detection circuit

[sneaker]

edge-detection

hi,all
can you give me some advices about edge-detection circuit?
is it a good design?

 

[wadaye]

Re: edge-detection

Hi sneaker:

You can detect edge just use 2 D-FFs and a XOR.

First u serilize the D-FFs, i.e. feed the second data_in of D-FF with the

first D-FF's Q, and then XOR these 2 D-FF's Q, and you get a edge-

detection for both posedge and negedge.

wang1

 

[tryagain]

Re: edge-detection

if simple,use fft can do it.

 

[sneaker]

edge-detection

wadaye,thanks.
the edge detection circuit is sensitive to glitches or not ?
I know how to get this circuit,but want to know whether can we use it in the digital design.

 

[gerade]

Re: edge-detection

wadaye's way is a synchronized way.

 

[mami_hacky]

Re: edge-detection

What kind of edges, do you want to detect? What do you mean by edge detection? do you want an edge detector, to detect the edges of an image?
If yes, you can implement a Canny edge detector with just a small effort and I think a two or three days of work. it is simple and straint forward. Canny of course is a really powerful edge detector, and you might not need to have such a good precision , then, if this is the case, you can simply compute the sqrt ( df(x,y)/dx^2 + df(x,y)/dy^2 ) value.

 

[sneaker]

edge-detection

mami_hacky
thanks,
it's not edge detection of a image.
just the edge as wadaye said,the edge of a digital signal.

 

[sneaker]

edge-detection

I want to finish the funtion of capture windows in the lcd controller.
From the hsync and vsync signal,pixel clock, to generate dataenable signal.
it belongs to sync processor.

 

[gentle_man]

edge-detection

pay attention to the clock uesed to detect edge is sync with the signal or not.

 

[jay_ec_engg]

Re: edge-detection

u can XOR the input signal with '0 ' and '1'... if op is '1' then its change of edge.... it will give nothing but glitcehs.....
but u cant test whether its positive or negative...
its simple funda..
jay

 

[tut]

Re: edge-detection

U can find positive and negative edge detection circuit details at the following URL :
h**p://www.allaboutcircuits.com/vol_4/chpt_10/5.html

* -> t

tut..

 

[wadaye]

Re: edge-detection

wadaye,thanks.
the edge detection circuit is sensitive to glitches or not ?
I know how to get this circuit,but want to know whether can we use it in the digital design.

The circuit is glitch free to generate the result. If you wanna use the

result, you'd better regerist it for glitch free.

By the way, I designed a TFT&STN Lcd_controller for a Arm-based SOC

chip last year, and it was passed the test after tape-out. If you have

questions about Lcd_Controller, you can contact me, maybe I can help

you.

wang1

 

[roger]

Re: edge-detection

at EDAboard/Digital signal processing

you can download e-book

digital image processing

it surely has some content you want. 8O

 

[sneaker]

edge-detection

wadaye,thank you very much.

how can I contact you?
can you leave you email address?

 

[sneaker]

edge-detection

roger, I can't find the e-book,
can you give me?

thank you very much1

 

[tom123]

Re: edge-detection

following code can detect edge in signal(both edge)

wire signal;
wire edge_detected;

reg signal_d;

always @(posedge clk or negedge rst_n)
begin
if (~rst_n)
signal_d <= #1 1'b0;
else
signal_d <= #1 signal;
end

assign edge_detected = signal ^ signal_d;


good luck;

hi,all
can you give me some advices about edge-detection circuit?
is it a good design?

 

[chihwt2003]

Re: edge-detection

Hi sneaker:

You can detect edge just use 2 D-FFs and a XOR.

First u serilize the D-FFs, i.e. feed the second data_in of D-FF with the

first D-FF's Q, and then XOR these 2 D-FF's Q, and you get a edge-

detection for both posedge and negedge.

wang1

Hi wang1,

May I ask how can I clock the D-Flipflop of ur suggested circuit??? May I know are there also any reference material that explain the woking of your circuit? Thanks.

CW

 

[jjww110]

edge-detection

if detect asynchronous signal edge,please use three
flip-flop