Forum Discussion
Honored ContributorTiming-Driven Synthesis is skipped...
When I run Quartus, I *always* get the message "Timing-Driven Synthesis is skipped because it could not initialize the timing netlist". This happens no matter what settings I use. Any idea what is going on? In case it matters, it is Quartus 9.0 SP2 on a 64-bit Vista machine. Thanks!
Later that day.... Same behavior on 32-bit Vista.11 Replies
Altera_Forum--- Quote Start --- When I run Quartus, I *always* get the message "Timing-Driven Synthesis is skipped because it could not initialize the timing netlist". This happens no matter what settings I use. Any idea what is going on? In case it matters, it is Quartus 9.0 SP2 on a 64-bit Vista machine. Thanks! Later that day.... Same behavior on 32-bit Vista. --- Quote End --- Hi, maybe this helps: The feature is available only for the TimeQuest Timing Analyzer and supports Arria II GX, Arria GX, Stratix series (except Stratix devices) and Cyclone series (except Cyclone devices), and HardCopy II devices. Altera recommends that you select a specific device for timing-driven synthesis to have the most accurate timing information. When auto device is selected, timing-driven synthesis uses the smallest device for the selected family to obtain timing information. Kind regards Gerd- Altera_Forum
Gerd,
Thanks very much. I have selected a specific Cyclone III device, but I still get this warning. I am attaching the settings file (with extension changed to .txt). One thing I wonder about is if this could be a Vista-related file access problem. - Altera_Forum--- Quote Start --- Gerd, Thanks very much. I have selected a specific Cyclone III device, but I still get this warning. I am attaching the settings file (with extension changed to .txt). One thing I wonder about is if this could be a Vista-related file access problem. --- Quote End --- Hi, I had brief look to your file, but I could not find a reason for ignoring the timing driving synthesis. I also use Vista for my Quartus runs, but it works in my projects. At least it told me that it is running. My current Quartus Version is 9.0 SP1. Did you try an older Quartus version ? Maybe it is a bug in SP2 ? Kind regards Gerd
- Altera_Forum
if there is a syntax error in your SDC file you may see this issue.
- Altera_Forum
Thanks very much for these comments. I put in a service request and was told that this will happen if there are *any* timing constraints that are valid in the fitter but not in synthesis. I am not clear if this will always be the case with SOPC systems with cpu.sdc, pll.sdc, and ddr_sdram_phy_ddr_timing.sdc, or if there are SOPC systems where timing-driven systhesis is possible. The NEEK reference design (cycloneIII_3c25_noisII_standard) is similar to my SOPC system and it does not seem like there would be any way to do it for that case because cpu.sdc always generates some filters that fail.
- Altera_Forum
is there anyway to discover which ones it complains about?
and does this warning matter? - Altera_Forum
I have tried two more things: removing the cpu.sdc file during systhesis, and synthesis using only one of the two cpus in the computer. No change; I get the same warning. There are now no warnings during synthesis of any kind related to timing constraints. So, if this really has to do with failing timing constraints thenI don't see a way to know which ones they are.
- Altera_Forum
Did you ever get this solved?
I changed a SDC file using standard Tcl constructs like if {} and foreach {} and so and got the 'dreaded' message. Turned out that A&S doesn't like the 'post_message' command, when I commented them out everything went fine again. - Altera_Forum
I've be having the same problem.
I've got two projects (CIII's, but different sizes) that are fairly similar, both using alot of the same constraints. One refuses to do timing driving synthesis, the other runs perfectly. I've tried going thru and removing the bit that are different to no effect so far. The error message is of course useless to try and track down the cause. Been meaning to file a tech support on it. I'm using post_message in the successful build. - Altera_Forum
I had had the same problem.
The solution had been to remove all spaces after line break backslashes. These are not tolerated, making the constraint invalid.
