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AMS Error: If I insert digital modules, analog circuits are not working as expected, if I delete digital modules, analog circuits are work normally

gordonqd

Hello,

   I create a config view to ams simulation, but if I insert digital modules, analog circuits are not working as expected. When VDD is 0V, VLDO is 1.7V, VDD is power and VLDO is LDO's output. If all digital modules are set as schematic view, analog circuits are still not working properly. If I delete digital modules, analog circuits are work normally. 

  • Can you post a pic of the top-level schematic and show how the VDD is coming into the circuit and connected to digital blocks? Also, identify what the digital blocks are.

  • in reply to tpylant

    Sorry, I don't have upload permission in our network.

    The digital blocks is a 3 to 8 Decoder. VDD is from analogLib's vpwl cell. 

    time1    1m

    voltage1  0

    time2    1.01m

    voltage2  2.0

    I set all cell view as shcematic, my circuit  doesn't have any verilog code.

    Partial irun.log show as below

    **** AMSD: Mixed-Signal Activity Statistics ****
    Number of A-to-D events: 6
    Number of A-to-D events in IEs: 6
    Number of D-to-A events: 7
    Number of D-to-A events in IEs: 7
    Number of VHDL-AMS Breaks: 0

    Partial ams_ieinfo.log show as below

    1. Interface Elements at the block <instance> COSIM of <master> COSIM (file : ./netlist.vams)
    Automatically inserted : COSIM.VSSX__Bidir_2__electrical
    Connect Module : Bidir_2
    Mode : Merged
    Net : COSIM.VSSX (discipline: logic, nettype: supply0)
    Port : COSIM.I7@LDO1_336T0<module>.VSSX (discipline: electrical, direction: inout, nettype: electrical)

    ……

    2. Interface Elements at the block <instance> COSIM of <master> COSIM (file : ./netlist.vams)
    Automatically inserted : COSIM.VLDO__Bidir_2__electrical
    Connect Module : Bidir_2
    Mode : Merged
    Net : COSIM.VLDO (discipline: logic, nettype: supply1)
    Port : COSIM.I7@LDO1_336T0<module>.VLDO (discipline: electrical, direction: inout, nettype: electrical)
    COSIM.I28@DEC_TC38_931BT2<module>.VDD (discipline: electrical, direction: inout, nettype: electrical)

    COSIM.I8@OPA_T0<module>.VDDX (discipline: electrical, direction: inout, nettype: electrical)

    (SpicePrimitiveTerminal electrical analog)

    Will AMS regard analog port as digitial port? 

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