Hi, I'm using Electric 8.09 on Mac OS X Snow Leopard running Java:
java version "1.6.0_15" Java(TM) SE Runtime Environment (build 1.6.0_15-b03-219) Java HotSpot(TM) 64-Bit Server VM (build 14.1-b02-90, mixed mode) I think there might be a possible SPICE deck generation bug. Consider this circuit: http://imagebin.ca/view/hHYxYJgE.html It is a column multiplexer. However, it does not have any explicit power/gnd connections. The body for PMOS should be at VDD and at GND for NMOS. Doing SPICE deck generation gives me this: *** WARNING: no power connection for P-transistor wells in cell 'colmux {sch}' *** WARNING: no ground connection for N-transistor wells in cell *'colmux{sch}' *** CELL: colmux{sch} .SUBCKT colmux Asel Asel_b Bsel Bsel_b bit bit0 bit0_b bit1 bit1_b bit_b mn...@0 bit0 Asel_b bit N L=0.6U W=2.4U mn...@1 bit1 Asel bit N L=0.6U W=2.4U mn...@2 bit0_b Bsel_b bit_b N L=0.6U W=2.4U mn...@3 bit1_b Bsel bit_b N L=0.6U W=2.4U mp...@4 bit1 Asel_b bit P L=0.6U W=2.4U mp...@5 bit0 Asel bit P L=0.6U W=2.4U mp...@6 bit0_b Bsel bit_b P L=0.6U W=2.4U mp...@7 bit1_b Bsel_b bit_b P L=0.6U W=2.4U .ENDS colmux Electric correctly warns about this. However, I am unable to simulate this circuit in LTSpice using C5_models.txt. LTSpice complains about not being able to find a suitable model. This is because the body connection is missing (i.e., the 4th terminal). Something like this should have been generated: mn...@0 bit0 Asel_b bit gnd N L=0.6U W=2.4U mp...@4 bit1 Asel_b bit vdd P L=0.6U W=2.4U This will simulate OK (at-least not give me errors about models not being found). I wonder if there is an option in Electric that a user can check to indicate that body connections should be implicit and Electric generates the 4th terminal connection as well for such circuits during SPICE deck generation. Maybe it should be turned on by default. Is this a bug? If so can it be fixed and can a patch be made available? Thanks. Kind regards. -- You received this message because you are subscribed to the Google Groups "Electric VLSI Editor" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/electricvlsi?hl=.
