Problem with a large system. Long Routing time

[breezy]

ise intermediate status

Hi, All
The whole system's been a good baby. Now as I put more unit into it, the routing seems taking forever with the intermediate status showing like only 1% unrouted. Here is the report:
Any suggestions?

"

Device utilization summary:

Number of External IOBs 49 out of 824 5%
Number of LOCed External IOBs 49 out of 49 100%

Number of MULT18X18s 24 out of 168 14%
Number of RAMB16s 54 out of 168 32%
Number of SLICEs 46590 out of 46592 99%

Number of BUFGMUXs 1 out of 16 6%
Number of TBUFs 1232 out of 23296 5%



Overall effort level (-ol): Standard (set by user)
Placer effort level (-pl): Standard (set by user)
Placer cost table entry (-t): 1
Router effort level (-rl): Standard (set by user)


Phase 1.1
Phase 1.1 (Checksum:ae0564) REAL time: 45 secs

Phase 2.2
.
Phase 2.2 (Checksum:1312cfe) REAL time: 2 mins 12 secs

Phase 3.3
Phase 3.3 (Checksum:1c9c37d) REAL time: 2 mins 13 secs

Phase 4.5
Phase 4.5 (Checksum:26259fc) REAL time: 2 mins 14 secs

Phase 5.8
...........................................................................................................................................................................................
Phase 5.8 (Checksum:f810989) REAL time: 9 mins 22 secs

Phase 6.5
Phase 6.5 (Checksum:39386fa) REAL time: 9 mins 23 secs

Phase 7.18
Phase 7.18 (Checksum:42c1d79) REAL time: 10 mins 28 secs

Phase 8.24
Phase 8.24 (Checksum:4c4b3f8) REAL time: 10 mins 28 secs

Phase 9.27
Phase 9.27 (Checksum:55d4a77) REAL time: 10 mins 29 secs

Writing design to file tps.ncd.

Total REAL time to Placer completion: 10 mins 54 secs
Total CPU time to Placer completion: 10 mins 47 secs


Phase 1: 310185 unrouted; REAL time: 11 mins 21 secs

Phase 2: 265654 unrouted; REAL time: 12 mins 25 secs

Phase 3: 166594 unrouted; REAL time: 13 mins 42 secs

Intermediate status: 8800 unrouted; REAL time: 43 mins 45 secs

Intermediate status: 6146 unrouted; REAL time: 1 hrs 13 mins 48 secs

Intermediate status: 5487 unrouted; REAL time: 1 hrs 43 mins 52 secs

Intermediate status: 4964 unrouted; REAL time: 2 hrs 13 mins 53 secs

Intermediate status: 4621 unrouted; REAL time: 2 hrs 43 mins 55 secs

Intermediate status: 4256 unrouted; REAL time: 3 hrs 13 mins 57 secs

Intermediate status: 4019 unrouted; REAL time: 3 hrs 43 mins 59 secs

Intermediate status: 3936 unrouted; REAL time: 4 hrs 14 mins 3 secs

Intermediate status: 3749 unrouted; REAL time: 4 hrs 44 mins 6 secs

Intermediate status: 3643 unrouted; REAL time: 5 hrs 14 mins 8 secs

Intermediate status: 3549 unrouted; REAL time: 5 hrs 44 mins 10 secs

Intermediate status: 3331 unrouted; REAL time: 6 hrs 14 mins 14 secs

Intermediate status: 3299 unrouted; REAL time: 6 hrs 44 mins 16 secs

Intermediate status: 3236 unrouted; REAL time: 7 hrs 14 mins 21 secs

Intermediate status: 3096 unrouted; REAL time: 7 hrs 44 mins 24 secs

Intermediate status: 3089 unrouted; REAL time: 8 hrs 14 mins 29 secs

Intermediate status: 3073 unrouted; REAL time: 8 hrs 44 mins 33 secs

Intermediate status: 2925 unrouted; REAL time: 9 hrs 14 mins 36 secs

Intermediate status: 2906 unrouted; REAL time: 9 hrs 44 mins 43 secs

Intermediate status: 2797 unrouted; REAL time: 10 hrs 14 mins 48 secs

Intermediate status: 2815 unrouted; REAL time: 10 hrs 44 mins 54 secs

Intermediate status: 2686 unrouted; REAL time: 11 hrs 15 mins

Intermediate status: 2634 unrouted; REAL time: 11 hrs 45 mins 2 secs

Intermediate status: 2657 unrouted; REAL time: 12 hrs 15 mins 7 secs

Intermediate status: 2630 unrouted; REAL time: 12 hrs 45 mins 12 secs

Intermediate status: 2566 unrouted; REAL time: 13 hrs 15 mins 19 secs

Intermediate status: 2491 unrouted; REAL time: 13 hrs 45 mins 22 secs

Intermediate status: 2440 unrouted; REAL time: 14 hrs 15 mins 31 secs

Intermediate status: 2434 unrouted; REAL time: 14 hrs 45 mins 34 secs

Intermediate status: 2386 unrouted; REAL time: 15 hrs 15 mins 38 secs

Intermediate status: 2340 unrouted; REAL time: 15 hrs 45 mins 51 secs

 

[banjo]

intermediate status unrouted

You still have over 2000 nets that are unrouted after 15 hours. Either the FPGA is out of resources, the placement that it picked is unroutable, or the extra unit you added has a very large amount of logic.

In the Place and Route properties box, you can change a couple of properties. For testing purposes, choose a low effort level and re-run the design. It should finish more quickly, but will not meet timing. If it finishes at all, then you know the design will fit and is routable.

Next, increase the effort level, and vary the placer cost table value. This varies the algorithm it uses to place the logic. For the type of designs we do, "10" seems to be a good seed value. However, other FPGAs and other types of designs will work better with other numbers. Try varying this to see which is better. You can also enable mutipass routing and have the tools cycle through a range of seed values keeping only the top few designs.

Finally, Xilinx tools are memory hogs. How much ram is installed in your machine? Less than 1 gig, can cause problems. The Xilinx tools can only optimize the amount of logic that it can hold in ram. If the design is larger than it can fit into available ram, the optimizer goes wonky and only optimizes in chunks.
Check your total ram usage in the reports from your last successful run. If this is close to the limit in the machine, then your additional unit has pushed you over the edge and you need more ram.

--- Steve
[/quote]

 

[echo47]

xilinx router 46592 slices

Number of SLICEs 46590 out of 46592 99%
Ouch! Try to simplify your logic.

Try to partition your modules with location constraints. Without location constraints, ISE creates a big bowl of spaghetti, and may have trouble routing everything. Example: I had a semi-full 2V6000 chip with everything running at 150 MHz. It was taking hours to route, unsuccessfully. I partitioned my modules into physical areas, and then it completed smoothly in 45 minutes.

Also try relaxing all your speed constraints to see if that's what's causing the slow routing.

If you aren't yet using ISE 8.1i, try it. In many cases it works a lot better than previous versions.