How to write compact DFF chain?

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davyzhu

Joined: 23 May 2004
Posts: 521
Helped: 3
Location: oriental

25 Mar 2006 3:04 How to write compact DFF chain?

Hi all,

Sometimes I have to write long DFF chain like below:

//------code--------------

Code:

...
reg [7:0] DFF0,DFF1,DFF2,...DFF50;

always@(posedge clk)
if(rst)
begin
DFF0 <= 0;
...
DFF50 <= 0;
end
else
begin
DFF0 <= INPUT;
...
DFF50 <= DFF49;
end

//------code end-----------
It's too long, is there any good compact style?

Any suggestions will be appreciated!
Best regards,
Davy

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linuxluo

Joined: 26 Jul 2002
Posts: 516
Helped: 4

25 Mar 2006 3:15 Re: How to write compact DFF chain?

hi,
1. why not using dft eda tools such as dftcompiler ?
2. you can using 1-d array and using for statement .

davyzhu

Joined: 23 May 2004
Posts: 521
Helped: 3
Location: oriental

25 Mar 2006 6:35 How to write compact DFF chain?

Hi linuxluo,

Sorry, but I am a newbie.
1. What's dftcompiler for?
2. Can you give me the example of 2?

Best regards,
Davy

leeenghan

Joined: 28 Dec 2004
Posts: 125
Helped: 7

25 Mar 2006 22:14 Re: How to write compact DFF chain?

Hi,

There is nothing long with the code; clarity is more important.

However, to make the code compact, I can think of the following:

1. Make them into one array. Then use something similiar to DFF[50:1] = DFF[49:0]; DFF[0] = input

2. Use a for loop

3. Use generate statement

Regards,
Eng Han
www.eda-utilities.com