[Milkymist-devel] Lastest sbapshot. Timing constraint not met

[Sébastien Bourdeauducq]

Hi,

I did not try to synthesize it with ISE 10.1; only 11.1 and 11.2 - and timing 
is met with both.

The 10.1 version could well be the source of the problem, as Xilinx regularly 
improves the performance of the synthesizer with each major release. You can 
get the 11.2 Webpack edition for free at the Xilinx website, and it's 
sufficient for building Milkymist.

For your information, 79% of the slices are occupied; and this snapshot is 
very close to the current SVN regarding the hardware design (only minor 
changes in the texture mapping unit and the AC'97 controller have been made).

Regards,
Sébastien


On Sunday 09 August 2009 20.23.50 Uwe Bonnes wrote:
> Hello,
>
> trying to get an overview on FPGA resource requirement, I downloaded the
> snapshot milkymist-20090709.tar.bz2, and started build_bitstream.sh in
> milkymist/milkymist-core. Reading synthesis.log, I see:
> Asterisk (*) preceding a constraint indicates it was not met.
>    This may be due to a setup or hold violation.
>
> --------------------------------------------------------------------------
>   Constraint                                |  Check  | Worst Case |  Best
>   Case | Timing |   Timing
>
>                                             |         |    Slack   |
>
>   Achievable | Errors |    Score
> ---------------------------------------------------------------------------
> * TSclkin = PERIOD TIMEGRP "clkin" 10 ns HI | SETUP   |    -0.511ns|
>   10.511ns|      11|        2720
>
> Toolchain used is ISE 10.1. Is this expected outcome? Any special things
> needed?
>
> Bye