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bug with parameter passing in nested subcircuits

		
	
				

			

									
					    haubmi
					
							

            
            			
				
									
											
			
			
				
			
			
			    	
			                    
                
				                on Apr 18, 2024 
				
			
			
		

		
		                    	    

        	    
Thread Summary

                The user reported a bug in LTspice where passing parameters to nested subcircuits fails, causing a 'Can't resolve .param' warning. The final answer confirmed it as a bug and stated that a fix is in development. QSPICE, while handling this correctly, has other issues such as inaccessible internal nodes and flattened netlists.
                        	    

                
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Hello,


there is a bug with parameter passing in nested subcircuits.


It is not limited to the netlist form, but to provide the minimal problem I have used the netlist below.


For the problem see the comment below.


.subckt top params: V=1
 V1 1 0 {V}
.ends top
 
.subckt sub params: V=1
 
 * passing parameter, working ok
 V1 1 0 {V}
 
 .subckt nested params: V=1
 V1 1 0 {V}
 .ends nested
 
 * top level with parameter passing, working ok
 X1 top params: V={V}
 
 * nested with default parameter, working ok
 X2 nested
 
 * nested with fixed parameter, working ok
 X3 nested params: V=2
 
***************************************************
********************bug in LTspice********************
* QSPICE has no problems with that (but other problems)
***************************************************
 * nested with parameter passing, not working ok
 * => WARNING: Can't resolve .param v=v
 X4 nested params: V={V}
***************************************************
 
.ends sub


.op


X1 sub params: V=1




I tested it with QSPICE also and it has no problem here (but another).


problem-nested_subckt_parameter.asc

			

			
									
		                             
                        

    

                                            
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