[SOLVED] 4 bit ripple counter using four D flip flops

[naavid]

4 bit ripple counter using four D flip flops without using other components. Can you please help.........

 

[rohitkhanna]

Config each DFF as a divide by 2 - i.e. connect Q/ to D and input clock to CLK.
Now connect them in series - Q1 - CLK2, Q2-CLK3, .... and so on.

And there you are !! A 4 bit binary counter

 

[naavid]

Dear Rohit, Really thanks. It works.............................

 

[babaduredi]

Config each DFF as a divide by 2 - i.e. connect Q/ to D and input clock to CLK.
Now connect them in series - Q1 - CLK2, Q2-CLK3, .... and so on.

And there you are !! A 4 bit binary counter

Hi Rohit,
This way we will get asynchronous counter. Is it possible to make synchronous one using dff alone?

 

[rids1]

module counterdff(clk,d0,d1,d2,q
);
input clk,d0,d1,d2;
output q;
reg q0,q1;
reg q;
always@(posedge clk)
begin
if(clk==1)
q0<=d0;

if(q0<=1)
q1<=d1;

if(q1<=1)
q<=d2;


end

endmodule
i done it by same maanner bt my code is nt synthesizing...plz tell me error