Fpga.Dev69
Guest
Wed Jul 20, 2011 8:07 pm
Dear sir,
I am working on the virtex 6, XC6VLX550T FF1759 speed grade -1 , using
finite state machines with high operands, (113 bits), in Galois field
inverse theory.
The problem I face is that I got such results :
Timing Summary:
---------------
Speed Grade: -1
Minimum period: 1.430ns (Maximum Frequency: 699.301MHz)
Minimum input arrival time before clock: 0.910ns
Maximum output required time after clock: 0.789ns
Maximum combinational path delay: No path found
=========================================================================
Process "Synthesize - XST" completed successfully
When i sent my paper to one of the journals, one of the reviewers said
that it is not possible that the virtex 6 goes beyond the 600Mhz. He
said try the place and route, but even though, I am getting the same
frequency...
Is is true that this frequency is a fake one or perhaps an error from
the synthetize tool.
Best Regards
Gabor
Guest
Wed Jul 20, 2011 8:07 pm
Fpga.Dev69 wrote:
Quote:
Dear sir,
I am working on the virtex 6, XC6VLX550T FF1759 speed grade -1 , using
finite state machines with high operands, (113 bits), in Galois field
inverse theory.
The problem I face is that I got such results :
Timing Summary:
---------------
Speed Grade: -1
Minimum period: 1.430ns (Maximum Frequency: 699.301MHz)
Minimum input arrival time before clock: 0.910ns
Maximum output required time after clock: 0.789ns
Maximum combinational path delay: No path found
=========================================================================
Process "Synthesize - XST" completed successfully
When i sent my paper to one of the journals, one of the reviewers said
that it is not possible that the virtex 6 goes beyond the 600Mhz. He
said try the place and route, but even though, I am getting the same
frequency...
Is is true that this frequency is a fake one or perhaps an error from
the synthetize tool.
Best Regards
These numbers (from the synthesis report) are estimates. Your only true
timing numbers come after place and route. You'll find them in the
post place & route static timing report. To get a meaningful timing
report, you should add timing constraints to the design so that the
tools have a target to try to achieve. With no constraints, the tools
will make some attempt at optimizing the speed, but perhaps not give
you the best possible results.
-- Gabor
Kolja Sulimma
Guest
Thu Jul 21, 2011 3:56 pm
On 20 Jul., 20:07, "Fpga.Dev69" <fpga.de...@gmail.com> wrote:
Quote:
Dear sir,
I am working on the virtex 6, XC6VLX550T FF1759 speed grade -1 , using
finite state machines with high operands, (113 bits), in Galois field
inverse theory.
The problem I face is that I got such results :
Timing Summary:
---------------
Speed Grade: -1
Minimum period: 1.430ns (Maximum Frequency: 699.301MHz)
Minimum input arrival time before clock: 0.910ns
Maximum output required time after clock: 0.789ns
Maximum combinational path delay: No path found
========================================================================
Process "Synthesize - XST" completed successfully
When i sent my paper to one of the journals, one of the reviewers said
that it is not possible that the virtex 6 goes beyond the 600Mhz. He
said try the place and route, but even though, I am getting the same
frequency...
Is is true that this frequency is a fake one or perhaps an error from
the synthetize tool.
Best Regards
It is definitely possible to go beyond 600MHz in a virtex-6.
(People where going to 250MHz in XC3195 14 years ago:
http://portal.acm.org/citation.cfm?id=278544 PDF available via
google)
However, for a state machine involving 113 bit operands described in
a high leve approach I seriously doubt your values..
Follow the advice of the other poster: Use post place and rout timing
and provide timing constraints for your clock signals to get a better
timing report.
Regards,
Kolja
