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Getting transistor instance name from spectre simulation for use in VerilogA

Jereme

Hello, 

I am trying to make some verilogA models for use in a Cadence simulation. I have a sample circuit with 9 transistors that are nshort and have names MN0-MN8. I invoke the model within the devices model card as follows: 

inline subckt nshort (d g s b)
parameters l=1 w=1 
nshort (d g1 s b) nshort_main w=w l=l 

vrts_nshort (g g1 s d b) rts_nshort w=w l=l 

....

ends nshort

Then the rts_nshort  is defined in a verilogA file as follows: 

`include "constants.h"
`include "discipline.h"
module rts_nshort(p,n,s,d,b);
inout p, n, s, d, b;
electrical p, n, s, d, b;
parameter real w=0;
parameter real l=0;
real dVg, tc, te;
real activate = 0;
real Vd = 0;
real Vg = 0;
real amp1 = 0;
real amp2 = 0;
real amp3 = 0;
real amp4 = 0;
real amp5 = 0;
real amp6 = 0;
real amp7 = 0;
real amp8 = 0;
real amp9 = 0;
real amp10 = 0;

analog begin

Vg = V(p,s);
Vd = V(d,s);

...

end

endmodule

 

In my testing with the help of some display statements I am able to determine that this VerilogA file is invoked for each nshort transistor in the design which is good, but the question is, it is possible to inform the verilogA code which transistor is currently being simulated?  For instance, it is currently simulating MN0, would it possible for the VerilogA file to be informed of this? I want to later use these transistor names to simulate specific activity in a device. 
So I guess overall, I am wondering When using Verilog-A models in Spectre, how can you identify the specific transistor instance that invokes the model? 


Thank you in advance for your help with this. 


Virtuoso version: 6.1.8-64b
Spectre version: 21.1.0.612.isr15
Let me know if there is any other tool version that would be helpful. 

  • A slightly unusual thing to do (usually accessing the instance name is done for reporting), but you can do it as follows (using an adaptation of your example):

    `include "constants.h"
`include "discipline.h"
module rts_nshort(p,n,s,d,b);
inout p, n, s, d, b;
electrical p, n, s, d, b;
parameter real w=0;
parameter real l=0;
real dVg, tc, te;
real activate = 0;
real Vd = 0;
real Vg = 0;
real amp1 = 0;
real amp2 = 0;
real amp3 = 0;
real amp4 = 0;
real amp5 = 0;
real amp6 = 0;
real amp7 = 0;
real amp8 = 0;
real amp9 = 0;
real amp10 = 0;

string moduleName;

analog begin

Vg = V(p,s);
Vd = V(d,s);

$swrite(moduleName,"%M");
// remove the ".vtrs_nshort" from the end
moduleName=moduleName.substr(0,moduleName.len()-13);
if (moduleName=="NM0") begin
  $strobe("Inside NM0");
end
$strobe("Module Name is ",moduleName);

end

endmodule

    Andrew

  • in reply to Andrew Beckett

    Hello Andrew, thank you for your reply. This was exactly what I was looking for, thank you!!!! 

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