From: Mark on
I need help. I get this error when I rout my design for my spartan 3:

WARNING:Route:438 - The router has detected an unroutable situation due to
local congestion. The router will finish the
rest of the design and leave one or more connections as unrouted. The
cause of this behavior might be putting too
much logic into a single CLB. To allow you to use FPGA editor to isolate
the problems, the following is a list of (up
to 10) such congested connections:

What can I do?

I use about 81% of the slice capacity.

Device utilization summary:
---------------------------

Selected Device : 3s200vq100-5

Number of Slices: 1570 out of 1920 81%
Number of Slice Flip Flops: 1662 out of 3840 43%
Number of 4 input LUTs: 2420 out of 3840 63%
Number used as logic: 2412
Number used as Shift registers: 8
Number of IOs: 27
Number of bonded IOBs: 27 out of 63 42%
Number of BRAMs: 4 out of 12 33%
Number of MULT18X18s: 9 out of 12 75%
Number of GCLKs: 5 out of 8 62%
Number of DCMs: 2 out of 4 50%


From: Symon on
Mark wrote:
> I need help.

Don't we all...

> I get this error when I rout my design for my spartan 3:
>
> WARNING:Route:438 - The router has detected an unroutable situation
> due to local congestion. The router will finish the
> rest of the design and leave one or more connections as unrouted.
> The cause of this behavior might be putting too
> much logic into a single CLB. To allow you to use FPGA editor to
> isolate the problems, the following is a list of (up
> to 10) such congested connections:
>
> What can I do?
>
Hi Mark,
I suggest you use FPGA editor to isolate the problems. If only you had a
list of congested connections!
Other alternatives including searching the internet for something like "The
router has detected an unroutable situation". There's this newfangled thing
called 'Google' (perhaps you've heard of it?) that you might use.
HTH., Syms.
p.s. Post a few of the listed congested connections so we can actually help
you. Your FPGA is nowhere near being full. My guess is maybe you've used too
many clocks in an IOB tile, but who can tell unless you post the
information?


From: HT-Lab on

"Mark" <Mark(a)mark.mark> wrote in message
news:480718d2$0$90272$14726298(a)news.sunsite.dk...
>I need help. I get this error when I rout my design for my spartan 3:
>
> WARNING:Route:438 - The router has detected an unroutable situation due to
> local congestion. The router will finish the
> rest of the design and leave one or more connections as unrouted. The
> cause of this behavior might be putting too
> much logic into a single CLB. To allow you to use FPGA editor to isolate
> the problems, the following is a list of (up
> to 10) such congested connections:
>
> What can I do?

I hit something similar some time ago when I was using incremental synthesis
in Precision (feed through ISE via smartguide). The design was around 80%
full but failed to route. When I turned off incremental synthesis it routed
it OK. If you are not using incremental synthesis/P&R then try changing your
synthesis/P&R settings.

Hans
www.ht-lab.com


>
> I use about 81% of the slice capacity.
>
> Device utilization summary:
> ---------------------------
>
> Selected Device : 3s200vq100-5
>
> Number of Slices: 1570 out of 1920 81%
> Number of Slice Flip Flops: 1662 out of 3840 43%
> Number of 4 input LUTs: 2420 out of 3840 63%
> Number used as logic: 2412
> Number used as Shift registers: 8
> Number of IOs: 27
> Number of bonded IOBs: 27 out of 63 42%
> Number of BRAMs: 4 out of 12 33%
> Number of MULT18X18s: 9 out of 12 75%
> Number of GCLKs: 5 out of 8 62%
> Number of DCMs: 2 out of 4 50%
>
>


From: Mark on
I have never used the FPGA editor before, but im going to read about it now.
:-)

"Symon" <symon_brewer(a)hotmail.com> wrote in message
news:fu78hi$hi4$1(a)aioe.org...

> HTH., Syms.

What is HTH., Syms?


From: Mark on
Thank you, i will try that.

"HT-Lab" <hans64(a)ht-lab.com> wrote in message
news:D7GNj.46980$4f4.21941(a)newsfe6-win.ntli.net...
>
> "Mark" <Mark(a)mark.mark> wrote in message
> news:480718d2$0$90272$14726298(a)news.sunsite.dk...
>>I need help. I get this error when I rout my design for my spartan 3:
>>
>> WARNING:Route:438 - The router has detected an unroutable situation due
>> to local congestion. The router will finish the
>> rest of the design and leave one or more connections as unrouted. The
>> cause of this behavior might be putting too
>> much logic into a single CLB. To allow you to use FPGA editor to
>> isolate the problems, the following is a list of (up
>> to 10) such congested connections:
>>
>> What can I do?
>
> I hit something similar some time ago when I was using incremental
> synthesis in Precision (feed through ISE via smartguide). The design was
> around 80% full but failed to route. When I turned off incremental
> synthesis it routed it OK. If you are not using incremental synthesis/P&R
> then try changing your synthesis/P&R settings.
>
> Hans
> www.ht-lab.com
>
>
>>
>> I use about 81% of the slice capacity.
>>
>> Device utilization summary:
>> ---------------------------
>>
>> Selected Device : 3s200vq100-5
>>
>> Number of Slices: 1570 out of 1920 81%
>> Number of Slice Flip Flops: 1662 out of 3840 43%
>> Number of 4 input LUTs: 2420 out of 3840 63%
>> Number used as logic: 2412
>> Number used as Shift registers: 8
>> Number of IOs: 27
>> Number of bonded IOBs: 27 out of 63 42%
>> Number of BRAMs: 4 out of 12 33%
>> Number of MULT18X18s: 9 out of 12 75%
>> Number of GCLKs: 5 out of 8 62%
>> Number of DCMs: 2 out of 4 50%
>>
>>
>
>