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Import spice netlist to schematic, problem with "netset" property

Fabrizio Mannozzi

Hello, I need help to import correctly spice to obtain the schematic of a digital library.
I have reported below the setting using to import the spice netlist
I have modified the device map and the netlist to remove any technology data.

Using SpiceIn tool from Virtuoso 6.1.8 the setting modified from default value are:
*****************************************************
-Input tab:
Netlist language: SPICE
Reference Library List: [technologyLibrary] basic
Trigger CDF parameters callback: [on]
Device Mapping File: [on]
spectre
master cell for ground node: gnd!

-Device Map (modified to remove technology data):
-- Device Mapping file generated from SpiceIn GUI
devSelect := n nmos
inhTerms := vdd! [@vdd!:%:vdd!] gnd! [@gnd!:%:gnd!]
propMap := w w l l
addProp := model nmos

devSelect := p pmos
inhTerms := vdd! [@vdd!:%:vdd!] gnd! [@gnd!:%:gnd!]
propMap := w w l l
addProp := model pmos
--
-Analog Sch Generation
Power Net Name: vdd!
Ground Net Name: gnd!

*****************************************************

In this example the spice netlist could be reduced to a single inverter:

.global vdd! gnd!

.subckt INV I O vdd! gnd!
M1 O I gnd! gnd! n w=1.5u l=0.5u
M2 O I vdd! vdd! p w=2.9u l=0.5u
.ends

*****************************************************
(The pins of schematics imported by SpiceIn are input-output but it can be solved by Andrew's script
"CCSupdatePinsDirectionFromSymInLib(lib)" found on the forum)

The schematic of inverter that I obtain after the import step has the pins of supply vdd! and gnd!
but it not possibile the setup the supply using the "netset" property of symbol and I need to setup
a net "vdd!" and "gnd!" on schematic that use these digital cells.

I suppose that it is possible to use the netset property to set the value of supply of cells but
with these setting it is not possible.
How can I import a schematic with power supplies settable through netset property?

Thanks,
Best Regards,
Fabrizio

Parents

  • Hello,

    I find a solution on forum and adapt it to work on all cells inside of library.

    This skill remove the IO pins of supply from schematic and call an Andrew skill to change the global net to inherit nets found on forum (CCSchangeGlobalsToInhConn.il).

    I need to remove the pins before to change the net from global to inherit otherwise an error occurs on supply pins.

    This is the skill used:

    procedure(deletePinsChangeGlobalsToInhConn(library)
    let((lib libName cellName cell cv c x)

    lib = ddGetObj(library)
    libName = lib~>name
    cellName = lib~>cells~>name

    foreach(cell lib~>cells
    when(ddGetObj(lib~>name cell~>name "schematic")
    cv=dbOpenCellViewByType(lib~>name cell~>name "schematic" "schematic" "a")
    inst=setof(c cv~>instances c~>cellName=="iopin")
    foreach(x inst
    dbDeleteObject(x)
    ); foreach
    printf("cellName: %L\n" cell~>name)
    CCSchangeGlobalsToInhConn(
    ?cellView cv
    ?mapList '(("vdd!" "vdd") ("gnd!" "gnd"))
    ?labelHeight 0.0625)

    schCheck(cv)
    dbSave(cv)
    dbClose(cv)
    );when
    );foreach

    );let
    );proc

Reply

  • Hello,

    I find a solution on forum and adapt it to work on all cells inside of library.

    This skill remove the IO pins of supply from schematic and call an Andrew skill to change the global net to inherit nets found on forum (CCSchangeGlobalsToInhConn.il).

    I need to remove the pins before to change the net from global to inherit otherwise an error occurs on supply pins.

    This is the skill used:

    procedure(deletePinsChangeGlobalsToInhConn(library)
    let((lib libName cellName cell cv c x)

    lib = ddGetObj(library)
    libName = lib~>name
    cellName = lib~>cells~>name

    foreach(cell lib~>cells
    when(ddGetObj(lib~>name cell~>name "schematic")
    cv=dbOpenCellViewByType(lib~>name cell~>name "schematic" "schematic" "a")
    inst=setof(c cv~>instances c~>cellName=="iopin")
    foreach(x inst
    dbDeleteObject(x)
    ); foreach
    printf("cellName: %L\n" cell~>name)
    CCSchangeGlobalsToInhConn(
    ?cellView cv
    ?mapList '(("vdd!" "vdd") ("gnd!" "gnd"))
    ?labelHeight 0.0625)

    schCheck(cv)
    dbSave(cv)
    dbClose(cv)
    );when
    );foreach

    );let
    );proc

Children
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