| Both sides previous revisionPrevious revisionNext revision | Previous revision |
| config:layout [2024/12/28 23:35] – [Diffusion] rajit | config:layout [2025/11/19 11:31] (current) – [Layout configuration options] rajit |
|---|
| Note that the ''layout.conf'' file is treated specially: all parameters within it are assumed to be within a ''begin layout''/''end'' block. | Note that the ''layout.conf'' file is treated specially: all parameters within it are assumed to be within a ''begin layout''/''end'' block. |
| |
| | <block 75%:0:#FFFFCC;black;1px dotted black;auto/10ptrounded>**Tip:** This configuration file is best written by someone who has completed some layout in the technology of interest. A design rule manual has a very large number of rules as it is supposed to cover all cases, whereas standard digital layout for cells and metal routing needs only a small subset of the rules. The ''layout.conf'' configuration file captures this subset.</block> |
| ===== General parameters ===== | ===== General parameters ===== |
| |
| int dummy_poly 0 # dummy poly | int dummy_poly 0 # dummy poly |
| int welltap_adjust 0 # welltap adjustment | int welltap_adjust 0 # welltap adjustment |
| | string gds_align "PR" # place and route boundary type for GDS |
| end | end |
| </code> | </code> |
| the well contact for n-type devices has to be moved down relative to its default generation. The ''welltap_adjust'' is set to the distance the contact for n-type transistor has to be moved down relative to its default location. | the well contact for n-type devices has to be moved down relative to its default generation. The ''welltap_adjust'' is set to the distance the contact for n-type transistor has to be moved down relative to its default location. |
| |
| | ''gds_align'' is used if GDS layers are specified. This is the GDS layer information for specifying the place and route boundary. |
| ==== Range tables ==== | ==== Range tables ==== |
| |
| This specifies the GDS layer names using ''layers'', and the corresponding major and minor layer number. When the ''gds'' section is specified, all material sections must provide two additional parameters: | This specifies the GDS layer names using ''layers'', and the corresponding major and minor layer number. When the ''gds'' section is specified, all material sections must provide two additional parameters: |
| * ''gds'', a string table of GDS layers (names) that should be generated for the abstract geometry | * ''gds'', a string table of GDS layers (names) that should be generated for the abstract geometry |
| * ''gds_bloat'', the amount the geometry should be bloated during layer generation | * ''gds_bloat'', the amount the geometry should be bloated during layer generation. If unspecified, this is taken to be zero. |
| * | * Optional items: |
| | * ''gds_mask'', a string table of GDS layers can be provided. When converting GDS layers back into abstract geometry, this mask will be used to filter out geometry when generating the abstract layer types. |
| | * ''gds_pin'', a pin layer used for metals only. This is where pins should be mapped. If unspecified, pins are mapped to the text layer (next). |
| | * ''gds_text'', a layer used for labels. If this is not specified, then the first ''gds'' layer for the material is used for labels as well. |
| | |
| For metal and via templates, the additional information is described in the template section. | For metal and via templates, the additional information is described in the template section. |
| ===== Base layer material names ===== | ===== Base layer material names ===== |
| string_table nfet "ntransistor" # fets | string_table nfet "ntransistor" # fets |
| string_table nfet_well ":ppdiff" # no pwell, but pplus diff exists | string_table nfet_well ":ppdiff" # no pwell, but pplus diff exists |
| | string_table pselect "pplus" # select layer |
| | string_table nselect "nplus" # select layer |
| end | end |
| </code> | </code> |
| int_table m1_gds_bloat 0 0 0 | int_table m1_gds_bloat 0 0 0 |
| </code> | </code> |
| | |
| | ==== Vias versus Contacts ==== |
| | |
| | The ''magic'' layout editor uses the notion of a contact to simplify via generation. Contact rules in ''magic'' are normally set so that the minimum contact size can fit a via plus the overlap required on the connected materials. A magic contact can be thought of as a macro that expands into three things: the via layer, and the two materials that are connected by the via. |
| | |