Speed improvements in FPGA

[B?rge Strand]

I guess I have stumbled over a fairly common issue: I've got my code
to work, but it's not fast enough.

What options do I have? Are there ways to use Xilinx tools to see
which parts of my code run the slowest? This is what I heard from a
friend: Try to cut down on the comparators. The synthesizer inserts
plenty of 6-bit comparators when it reads my code. That can't be good.
I want to make most comparators compare equality to zero. That should
be way faster than >= 12 for instance.

The resources I've found online are mostly for courses that charge
heavy cash. What free resources are out there?

Greetings,

Břrge

 

[Swapnajit Mittra]

if (~|should_be_zero)
....

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[Petter Gustad]

borge.strand@gmail.com (B?rge Strand) writes:

What options do I have? Are there ways to use Xilinx tools to see
which parts of my code run the slowest? This is what I heard from a

trce

Petter

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A: Because it messes up the order in which people normally read text.
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Create a UCF (user constraint file) and put constraints on
signals:

PERIOD
MAXDELAY
Then make iterative runs with tighter constraints.
Bill

 

[Marko]

What part are you targeting and how fast are you trying to go? Have
you applied any timing constraints?

Assuming that you're using Xilinx tools, you can use the timing
analyzer to identify the specific problem paths.

If your code includes multiple modules, you can built them separately
and see how fast each one will run.

Can you post your code or provide a link to it? I'm sure that will
get you lots of interesting replies.

Marko


On 19 Dec 2004 05:26:55 -0800, borge.strand@gmail.com (B?rge Strand)
wrote:

I guess I have stumbled over a fairly common issue: I've got my code
to work, but it's not fast enough.

What options do I have? Are there ways to use Xilinx tools to see
which parts of my code run the slowest? This is what I heard from a
friend: Try to cut down on the comparators. The synthesizer inserts
plenty of 6-bit comparators when it reads my code. That can't be good.
I want to make most comparators compare equality to zero. That should
be way faster than >= 12 for instance.

The resources I've found online are mostly for courses that charge
heavy cash. What free resources are out there?

Greetings,

Břrge