I've used Encounter 8.1 for past projects to generate sdf back-annotation for simulation and it worked great. Now we've moved to Encounter 9.1, but the exact same 8.1 encounter project reloaded in 9.1 gives different results. First of all, the middle field ("typical", my guess) is no longer present, and when I load the sdf in a simulator the delays are all taken as 0 (no delays). Second, the delays for interconnect are different, and quite often 0. Another difference I noticed is that in 8.1 the value triplets were always the same (which I thought odd), but not in encounter 9.1.
What am I missing? I'm almost sure it's just a setting, but I can't see where or how.
U134/A (0.0037:0.0037:0.0037) (0.0037:0.0037:0.0037))(INTERCONNECT
I_SCLK Q_TRANSACTIONCOMPLETE_REG/CKN (0.0045:0.0045:0.0045)
U134/A (0.003::0.004) (0.003::0.004))(INTERCONNECT I_SCLK
Q_TRANSACTIONCOMPLETE_REG/CKN (0.000::0.000) (0.000::0.000))
Here is what I do through the GUI, with a little more detail, (same for both versions).
1- Start encounter2- Restore design from an encounter format3- Do RC extract (simplest kind, not sign-off)4- Calculate timing
It translates to the following commands in the log file, after loading the project:
Encounter 8.1: <CMD_INTERNAL> isExtractRCModeSignoff<CMD> extractRC<CMD> delayCal -sdf SPI_Demo_8.1.sdf -idealclock
Encounter 9.1:<CMD> extractRCExtraction called for design 'SPI_Demo' of instances=169 and nets=130 using extraction engine 'preRoute' .<CMD> write_sdf -ideal_clock_network SPI_Demo_9.1.sdf
So no, it doesn't specify the views :(. I looked in the command documentation and found the info on -max/min/typ_view and the -view switches. It looks like what I'm looking for, because the -view switch mentions it doesn't populate the typ slot. This is great news, but I have 3 other questions:
1- The commands require a "viewName" argument. What's this and how do I know what to give as argument? The documentation is not very detailed on this point.2- The switches are said to be used in Multi Mode Multi Corner analysis, but I haven't done this yet (unless the Extract RC does this without telling me). I'm pretty sure it should be standard verification for sign-off, but for now I just want a quick'n dirty annotation file. Do I really have to do corner analysis at this point?3- Can you set this option in the GUI? Everything will end up in a script, but it's always nice to have GUI handy.