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RC could not find scan equivalent cell

Lamech
Hi, I am a relatively new to cadence tools. I am trying to insert scan chain into my design. But getting the following error... "Could not find a scan-equivalent cell. DFT-510. I have added the test_cell group as specified in the documentation. Also I have set dont_use, dont_touch attributes to false in .lib file. In the RC tcl file I have set "set_attribute preserve false SCANFF" and "set_attribute avoid false SCANFF". I have tried both Muxed scan style and LSSD scan style with different cells. Can some one tell me what could be the problem? or any suggestions on scan chain design in cadence? Kind of show stopper in our project, so any help will be highly appreciated... Thanks in Advance, Charles

  •  Hi Charles,

     seems like a library problem. if you can send the .lib for your non-scan and scan equivalent or the output of 

     ls -al [find / -libcell <scan/nonscan cell>

     we may be able to help

     You can also try the command

    Usage: set_scan_equivalent -non_scan_cell <libcell> -scan_cell <libcell> [-tieoff_pins <string>] [-pin_map <string>]

        -non_scan_cell <libcell>:
            the non-scan cell to be replaced
        -scan_cell <libcell>:
            the scan cell to map to
        [-tieoff_pins <string>]:
            a list of the form "{{<pin> <tieoff_value>} ... {<pin> <tieoff_value>}}" indicating the various scan pins and their respective active values
        [-pin_map <string>]:
            a list of the form "{{<non-scan pin> <scan pin>} ... {<non-scan pin> <scan pin>}}" indicating the equivalence between pins with different names in the scan and non-scan
            cells

    Note that, it should work out of the box so if you need to use set_scan_eq there is probably something wrong with the library or RC but it may also provide you some useful feedback as to what the root cause is

    regards,

    gh-

  •  BTW, please post RC questions on logic design forum

     gh-

  • Hi Grasshopper, Thanks for the reply. I dont know whether I can continue this thread here in this forum! I am attaching a file which has scan and non scan cell description, its not the complete .lib file though... Thanks Again, Charles

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