Dear all
I need some help to interpret correctly HSPICE's results concerning probes.
my spice file is test.net
Code:*
hdl 'probe.va'
v1 1 0 10
x1 1 0 probe r=1
.op
.end
Case 1 : I use the following veriloga file Code:module probe(p, n);
inout p, n;
electrical p, n;
parameter real r=1 exclude 0;
analog
$display("##%g",I(p));
endmodule
For this current probe HSPICE outputs:
##-2e+14
Case 2: Change the unnamed branch as follows Code:$display("##%g",I(p,n));
Output is:
##-0
Case 3: Change the branch current probe to port current probe Code:$display("##%g",I(<p>));
Output is:
##-0
Case 4: Add a new branch and probe its flow Code:branch (p,n) bprobe;
...
$display("##%g",I(bprobe));
Output is :
##-2e+14
Case 5: contribute to the unnamed branch Code:module probe(p, n);
inout p, n;
electrical p, n;
branch (p,n) bprobe;
parameter real r=1 exclude 0;
analog begin
I(p,n) <+ V(p,n)/r;
$display("##%g",I(bprobe));
end
endmodule
Output is :
##-5
Renew all these 5 examples with a current source connected to the veriloga instance to obtain case 6 to 10
HSPICE outputs -5 for all the cases
These results are confusing.
For Case 1 and Case2, it seems that a minimal conductance is used to avoid the short circuit of the voltage source but why Case2 and Case2 are giving differents results. Case3 and Case4 seems ok but how interpret Case5 ?.
Similar questions for the current source cases.
Need help to interpret these results.
Best regards