Using "Dot - notation" in verilog ???

[Taha]

Dear all,

I was using Vituoso Composer - Schematic (from Cadence Design Systems)
to generate a netlist for me and in one of the modules I got the
following statement.

mbe I0 ( .x2(x[1]), .x1(x[0]), .x0(cds_globals.GND_),
..s_inverted(s_inverted[0]), .s(s[0]), .m2(m2[0]), .m1(m1[0]),
.VSS(VSS), .VDD(VDD));

The module delcaration for an mbe is included below.

Does anyone know what that third parameter is trying to say... i.e.
what does cds_globals.GND_ mean?

I tried to extrapolate from my C knowledge thinking that it was a
variable in the cds_globals module (i.e. I created a module called
cds_globals and declared a GND_ variable of type reg and initialized it
to 0) but the compiler still complains about that line.

Any comments would be appreciated.

Thanks,

Taha

///////////////////////////////////////////////////////////
module mbe ( m1, m2, s, s_inverted, VDD, VSS, x0, x1, x2 );
output m1, m2, s, s_inverted;

inout VDD, VSS;

input x0, x1, x2;


specify
specparam CDS_LIBNAME = "BOOTH_COMP_MULT";
specparam CDS_CELLNAME = "mbe";
specparam CDS_VIEWNAME = "schematic";
endspecify

buf_I1_D1 I4 ( .a1(x2), .z(s), .VSS(VSS), .VDD(VDD));
inv_I1_D1 I3 ( .a1(x2), .z(s_inverted), .VSS(VSS), .VDD(VDD));
nor_I2_D1 I2 ( .a2(net30), .a1(m1), .z(m2), .VSS(VSS), .VDD(VDD));
xor_I2_D1 I1 ( .a2(x1), .a1(x0), .z(m1), .VSS(VSS), .VDD(VDD));
xnor_I2_D1 I0 ( .a2(x2), .a1(x1), .z(net30), .VSS(VSS), .VDD(VDD));

endmodule

 

[Swapnajit Mittra]

Most likely it is ground signal. Try putting a 1'b0 in place of
cds_globals.GND_.

- Swapnajit.

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[Andy Peters]

Taha wrote:

Dear all,

I was using Vituoso Composer - Schematic (from Cadence Design Systems)
to generate a netlist for me and in one of the modules I got the
following statement.

mbe I0 ( .x2(x[1]), .x1(x[0]), .x0(cds_globals.GND_),
.s_inverted(s_inverted[0]), .s(s[0]), .m2(m2[0]), .m1(m1[0]),
.VSS(VSS), .VDD(VDD));

The module delcaration for an mbe is included below.

Does anyone know what that third parameter is trying to say... i.e.
what does cds_globals.GND_ mean?

cds_globals is a module instance, and GND is a signal within that
module. You need to make sure you compile that module.

-a

 

[Taha]

Thanks Andy for the prompt response....

I have compiled the module but I havent instantiated it ... That is
probably my error... I'll see if that change works...

Thanks...

 

[Taha]

It is a ground signal (i know that since i drew the schematic )

But there are approximately 20 of them all across my design and it will
increase. Hence i'd prefer if I have to change the netlist that is
generated.

-- Taha