Support Forum
How to import DEF file
YC
Friday 29th August 2025 I want to open a DEF file which includes several SRAM macros. But, below erros are shown: Errors: 4 Cellref(s) can not be resolved. Empty cell added. (RA1TSNHSMB2048X1X128M4UPG, RA1TSNUHD512X1X128M4LPG, RF2TSNHD512X128X1M2UPG, RF2TSNUHD256X128X1M2LPG) Though I try to attach the 4 related SRAM LEF file first and then read the DEF again, the error still exists. Please help to advice the correct flow to import DEF file. Thanks.
Friday 29th August 2025 I want to open a DEF file which includes several SRAM macros. But, below erros are shown: Errors: 4 Cellref(s) can not be resolved. Empty cell added. (RA1TSNHSMB2048X1X128M4UPG, RA1TSNUHD512X1X128M4LPG, RF2TSNHD512X128X1M2UPG, RF2TSNUHD256X128X1M2LPG) Though I try to attach the 4 related SRAM LEF file first and then read the DEF again, the error still exists. Please help to advice the correct flow to import DEF file. Thanks.
Jürgen
LayoutEditorFull
Friday 29th August 2025 At first loading/attaching all required LEF files and then attach the DEF file is the correct order to load you design. Please check if the missing LEF-cells are loaded before the DEF is attached and exactly spelled in the same way. If not, please check the LEF files if they really contain the required macros. In case the LEF files contains the macros and they are not loaded, please send an example LEF file to our support ( support@layouteditor.com ), we are happy to review it. However, in most case the problem is just related the use of incorrect capital/small letters in the macro names,
LayoutEditorFull
Friday 29th August 2025 At first loading/attaching all required LEF files and then attach the DEF file is the correct order to load you design. Please check if the missing LEF-cells are loaded before the DEF is attached and exactly spelled in the same way. If not, please check the LEF files if they really contain the required macros. In case the LEF files contains the macros and they are not loaded, please send an example LEF file to our support ( support@layouteditor.com ), we are happy to review it. However, in most case the problem is just related the use of incorrect capital/small letters in the macro names,
YC
Monday 1st September 2025 Thanks a lot. Now the DEF is displayed by attaching LEF first and then attaching DEF file. When I do modification on DEF and want to save it, it shows "no netlist loaded". How could I load the netlist? Thanks.
Monday 1st September 2025 Thanks a lot. Now the DEF is displayed by attaching LEF first and then attaching DEF file. When I do modification on DEF and want to save it, it shows "no netlist loaded". How could I load the netlist? Thanks.
Jürgen
LayoutEditorFull
Monday 1st September 2025
Attachments:
(only for registered users)
screensho.png
Ok, the error message at that point can be confusing, we will improve that. With any DEF file load the file content is converted to GDS and its netlist is loaded. The netlist can be view inside the netlist dock window. (right click on an empty part of the toolbar to view it or using any netlist feature to do so). Any cell of the LayoutEditor can have 3 netlist: one from the schematic, one extracted and one loaded. When saving to DEF the extracted netlist will be created if not done before. So a correct layer setup of the conductive layers and via layers is important. This can for example be extracted from your technology LEF file or maually entered in the LayerManager. Next to the extracted netlist showing the existing connection a second netlist is needed showing the required connections. This second netlist can be the netlist from the schematic or a loaded netlist. Please choose in the dock the correct netlist you want to save into the DEF:  If the extracted netlist is choosen, the menioned error message show up.
LayoutEditorFull
Monday 1st September 2025
Attachments:
(only for registered users)
screensho.png
Ok, the error message at that point can be confusing, we will improve that. With any DEF file load the file content is converted to GDS and its netlist is loaded. The netlist can be view inside the netlist dock window. (right click on an empty part of the toolbar to view it or using any netlist feature to do so). Any cell of the LayoutEditor can have 3 netlist: one from the schematic, one extracted and one loaded. When saving to DEF the extracted netlist will be created if not done before. So a correct layer setup of the conductive layers and via layers is important. This can for example be extracted from your technology LEF file or maually entered in the LayerManager. Next to the extracted netlist showing the existing connection a second netlist is needed showing the required connections. This second netlist can be the netlist from the schematic or a loaded netlist. Please choose in the dock the correct netlist you want to save into the DEF:  If the extracted netlist is choosen, the menioned error message show up.
YC
Tuesday 2nd September 2025 Shall I load netlist first and then attach LEF and DEF? Or, shall I attach LEF/DEF first and then load netlist? When I try to import netlist in Netlist dock window, it shows "Unsupported Entry". My netlist is verilog netlist synthesized by CAD tool such as DesignCompiler. Thanks.
Tuesday 2nd September 2025 Shall I load netlist first and then attach LEF and DEF? Or, shall I attach LEF/DEF first and then load netlist? When I try to import netlist in Netlist dock window, it shows "Unsupported Entry". My netlist is verilog netlist synthesized by CAD tool such as DesignCompiler. Thanks.
Jürgen
LayoutEditorFull
Tuesday 2nd September 2025 A DEF file usually contains the netlist and it is loaded with the DEF file. So no additional loading set is required. Just double check if really the netlist is present in your DEF and the loaded netlist is used for DEF export. In case the extracted netlist or schematic netlist is currently displayed in the subwindow, the DEF export may result in the mentioned error message. If a netlist is loaded you will find all devices and routes under the corresponding tab in that subwindow.
LayoutEditorFull
Tuesday 2nd September 2025 A DEF file usually contains the netlist and it is loaded with the DEF file. So no additional loading set is required. Just double check if really the netlist is present in your DEF and the loaded netlist is used for DEF export. In case the extracted netlist or schematic netlist is currently displayed in the subwindow, the DEF export may result in the mentioned error message. If a netlist is loaded you will find all devices and routes under the corresponding tab in that subwindow.
YC
Wednesday 3rd September 2025 There is no netlist included in my DEF file, since it is a large design and DEF file is only used to specify SRAM/macro location in my flow. For such case, how could I load the netlist? Thanks.
Wednesday 3rd September 2025 There is no netlist included in my DEF file, since it is a large design and DEF file is only used to specify SRAM/macro location in my flow. For such case, how could I load the netlist? Thanks.