Hi all I am stuck with the lvs error ```Subcircuit summary: Circuit 1: x6_bit_dac ...
p
Hi all I am stuck with the lvs error
Copy code
Subcircuit summary:
Circuit 1: x6_bit_dac                      |Circuit 2: 6_bit_dac                       
-------------------------------------------|-------------------------------------------
sky130_fd_pr__nfet_g5v0d10v5 (120)         |sky130_fd_pr__nfet_g5v0d10v5 (120)         
sky130_fd_pr__pfet_g5v0d10v5 (120)         |sky130_fd_pr__pfet_g5v0d10v5 (120)         
switch2n_3v3 (16)                          |switch2n_3v3 (16)                          
Number of devices: 256                     |Number of devices: 256                     
Number of nets: 163 **Mismatch**           |Number of nets: 162 **Mismatch**           
---------------------------------------------------------------------------------------
NET mismatches: Class fragments follow (with fanout counts):
Circuit 1: x6_bit_dac                      |Circuit 2: 6_bit_dac
How do I find where is the extra net coming from in the layout ? I double checked the 6_bit_dac layout and upto 5bit_dac everything was lvs clean. I have attached the comp.out file, and both the netlist for layout and schematic along with the screenshot for the schematic. Thank you.
m
In the netlist,
VCC
is connected to all the cells
Copy code
(no matching net)                          |Net: VCC                                   
                                           |  sky130_fd_pr__pfet_g5v0d10v5/(1|3) = 60  
                                           |  sky130_fd_pr__pfet_g5v0d10v5/4 = 120     
                                           |  switch2n_3v3/VCC = 16                    
---------------------------------------------------------------------------------------
while in the layout it is split into 2 nets that are not connected at the top level.
Copy code
Net: x5_bit_dac:5_bit_dac_0[1]/VCC         |(no matching net)                          
  sky130_fd_pr__pfet_g5v0d10v5/(1|3) = 30  |                                           
  sky130_fd_pr__pfet_g5v0d10v5/4 = 60      |                                           
  switch2n_3v3/VCC = 8                     |                                           
                                           |                                           
Net: x5_bit_dac:5_bit_dac_0[0]/VCC         |(no matching net)                          
  sky130_fd_pr__pfet_g5v0d10v5/(1|3) = 30  |                                           
  sky130_fd_pr__pfet_g5v0d10v5/4 = 60      |                                           
  switch2n_3v3/VCC = 8                     |
Check the layout top level
VCC
connections.
p
Ok let me check