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Subject: Bob, 2 questions about Encounter DB

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eminemshow
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5/08/2008 3:10 AM
Bob, need your help 1st, I want get all the clock source in SOC Encounter, I use the dbIsFTermTAClkSrc to get the clock defined at primary input, but it doesn't work? Is it a command only supprot FE timing engine? Is there any equivalents db commands? Also, for clocks defined at instance terms, how can I get the clock definition term? My purpose it to get a list of the following format: SDC_CLOCK_NAME term_or_fterm_name 2nd, I want to make a table lookup in SOC-E db, can I get the delay value if I have the input transition and output load, then I can use SOME db command to get specific arc delay? Many thanks!!

BobD
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5/08/2008 6:59 AM
Hello, Great questions! Thank you for posting them. For querying the db for timing information, CTE-TCL commands are definitely the way to go. Commands like "dbIsFTermTAClkSrc" is what I call an FE-TCL command and they're clumsy to work with for timing purposes. CTE-TCL command documentation can be found in the FE Text Command Reference under the "Advanced Timing Tcl Scripting Commands". Here is an example of how you could use CTE-TCL commands to find the name and source of all the clocks defined in the design: "timeDesign" and then: encounter 9> foreach_in_collection clock [all_clocks] {Puts "[get_property $clock hierarchical_name] [get_property [get_property $clock sources] hierarchical_name] vclk1 DTMF_INST/TEST_CONTROL_INST/i_150/Y vclk2 DTMF_INST/TEST_CONTROL_INST/i_156/Y I don't know the answer to your second question straight away. I seem to recall seeing a textual display of the lookup table for a given library cell in the past, which may be helpful, but I can't find the command that produces that table right now. There's the "report_cell_instance_timing" command, but I don't think that's quite what you're looking for. Let me do some research. I'll post back if/when I find an answer for this part. If anyone else has a suggestion, please do share. Hope this helps, Bob

eminemshow
Posts: 75
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5/09/2008 7:11 AM
Bob, Today, I just make a try using the FE timing engine. I compare the results of CTE & FE timer, the worst path is the same. I think the reason is that they both use SignalStorm as the delay calculator, maybe they have difference in building timing graphs. I have to admit that FE-timer has limited timing report ability. But I can use commands like 'dbForEachHeadPath, dbForEachPathTerm, dbPathRiseDelay, dbPathFallDelay' and 'dbIsTerm(FTerm)TAClkSrc' to make my 1st question solved. But for the 2nd one, I am waiting for your solution. Thanks again!Take a bow!

BobD
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5/13/2008 8:11 AM
Regarding your 2nd question... The "reportTimingLib" command is the one I was thinking of. It prints out a text report of the lookup tables for a given library cell. Though this is not a programmatic interface into the lookup tables, it may give you a path to the information you're looking for. Hope this helps, Bob

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