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  3. Internal error with topology.c

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Internal error with topology.c

CPete
CPete over 14 years ago

Hi,

 When I try to run a Spectre dc and trans simulation with my 8-bit-adder circuit, have an internal error stopping the simulation.  I get the following messages in the spectre log window:

1) the usual "unable to compile ahdlcmi module library" message (which has not stopped my simulations in the past),

2) a warning from spectre during initial setup about having PMOS and NMOS from the driver circuit running at 1 A/exceeding imelt = 10 mA (the test driver/load circuit provided by our course instructor)

3) "Internal error found in spectre during topology check, during initial setup." --> "Assertion failed in file 'topology.c' at line 1008"

 

Any ideas how to interpret error #3??  I've done the Virtuoso save and check with no error for the 8-bit-adder or any of the lower schematics in the hierarchy.

To explain how I'm implementing an 8-bit-adder:  The design is four 2-bit-adders linked together.  Each 2-bit-adder is made of 2 individual adders.  Individual adders have Carry Out implemented with CMOS and Sum implemented with pass-logic transistor gates.

 

Thank you for your time.

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  • Andrew Beckett
    Andrew Beckett over 14 years ago

    I can't really see how that would help, since presumably the resulting netlist would be the same - spectre has no visibility of the schematic. I can only assume that something subtle changed which allowed it to proceed.

    Most universities would be using more recent versions than that - even if the IC version is old. But I agree, things may be more constrained there.

    Andrew.

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  • Andrew Beckett
    Andrew Beckett over 14 years ago

    I can't really see how that would help, since presumably the resulting netlist would be the same - spectre has no visibility of the schematic. I can only assume that something subtle changed which allowed it to proceed.

    Most universities would be using more recent versions than that - even if the IC version is old. But I agree, things may be more constrained there.

    Andrew.

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