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connecting a power pad to a macro pin

gops
In my design, there is an One time programmable Memory (OTP).It has 4 power supply pins, VDD, VSS,VPP. The connection of VDD and VSS is similar to the VDD and VSS of the standard cells.( I have connected them with global net connect and sroute) But for VPP , I have used dedicated core power pads(VDD core), but the problem is I cant connect these pads to the VPP pin > My requirement is I need to connect the VDDCORE (cell type) pad named PotpVPP(instance name) to VPP pin of the OTP named tsmc_13_nv_otp(cell type) with u_otp(instance name) .Is this possible using global net connect? In short how can i connect the VDD pin of a particular power pad ( PotpVPP) to the macro pin named VPP

  • Hi,

    A globalNetConnect should make it. Use the "-override" switch as below in case you already assign a special net to the VDD pin of the power pad.

    1/ Create a VPP_net (or wahtever) power net  in the initFe.conf

    2/ Make sure the VPP pin of the Memory is defined as a POWER pin in the LEF.

    3/ globalNetConnect:

    globalNetConnect VPP_net   -type pgpin   -pin VPP   -singleInst  yourRamInstName   -override   -verbose

    globalNetConnect VPP_net   -type pgpin   -pin VDD   -singleInst  yourPowerPadInstName   -override   -verbose

     Stéphane.

     

  • Hi Stephane,

    I tried the commands you told, but when I did sroute , my VPP pad dont get routed.Can you please give me the sroute command for routing this VPP pad .

  • Hi,

     

    Not easy to reply. If the Global connection is done then you should be able to ask Sroute to connect your power pad pin to the power ring.  There is an option for that in Sroute. You can also check that the power pin in the LEF as a "USE POWER" or "USE GROUND" statement.

     

    Best regards.
    Stéphane.

     

  •  You can try drawing the connection by  hand - sometimes that will point out the problem for why Sroute is not doing it. (Maybe a routing blockage, DRC violation, etc.) 

  • Hi,
     
    When I tried the commands I got the following warnings and errors.Please see below( copied from log file)
     
    <CMD> globalNetConnect VPP -type pgpin -pin VPP -singleInst u_sp/otp/u_otp0 -override -verbose

    0 new pwr-pin connection was made to global net 'VPP'.

    <CMD> globalNetConnect VPP -type pgpin -pin VPP -singleInst VPP -override -verbose

    0 new pwr-pin connection was made to global net 'VPP'.

    sroute -connect { blockPin padPin } -layerChangeRange { 1 6 } -blockPinTarget { nearestRingStripe nearestTarget } -padPinPortConnect { allPort oneGeom } -deleteExistingRoutes -checkAlignedSecondaryPin 1 -blockPin useLef -allowJogging 1 -crossoverViaBottomLayer 1 -allowLayerChange 1 -targetViaTopLayer 6 -crossoverViaTopLayer 6 -targetViaBottomLayer 1 -nets { VPP }

    Begin power routing ...

    **WARN: (SOCSR-1256): Net VPP does not have CORE class pad pins to be routed.

    Please check net list or port class.

    Net VPP does not have AREAIO class pad pins to be routed.

    Please check net list or port class.

    Number of Block ports routed: 0 open: 2

    End power routing: cpu: 0:00:00, real: 0:00:00, peak: 485.00 megs.


    thanks

    gopakumar

  •  Check the LEF for the IO pad. The core-facing VPP pin needs to be CLASS CORE, like this example:

     

        PIN VDD
            USE POWER ;
            DIRECTION INOUT ;
            PORT
            CLASS CORE ;
            LAYER...
            RECT.... etc.

     

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