Could you explain the meaning of a verilog-AMS code?

[Robert Willy]

Hi,

I come across the following code from verilog-AMS reference book. First of
all, it is found that I have to comment out

// wire dnet;


or

// ddiscrete dnet;

in order a verilog-AMS simulation software (SMASH) to work.

What is the meaning of the above two attributes?

It has:

electrical anet;


'dnet' has obvious electrical attribute? I feel that it is weird to have

'electrical anet;'


Could you explain it to me?



Thanks,







module a2d(dnet, anet);
input dnet;
output anet;
wire dnet;
ddiscrete dnet;
electrical anet;
real avar;
analog begin
if (dnet === 1'b1)
avar = 5;
else if (dnet === 1'bx)
avar = avar; // hold value
else if (dnet === 1'b0)
avar = 0;
else if (dnet === 1'bz)
avar = 2.5; // high impedance - float value
V(anet) <+ avar;
end
endmodule