System and method for utilizing meta-cells
Exemplary systems and methods of laying out integrated circuits are disclosed. The systems include a layout application configured to place geometries in conformance with layout constraints transformed into composite cells. A composite cell defines a relationship between one or more cells, such as parameterized cells, and is independent of the physical topology of the cells. The exemplary systems are configured to use the composite cells to restrict a number of possible layout scenarios by generating a first layout scenario in conformance with the composite cell implementations, and to thereafter generate a second layout scenario in conformance with the constraints on all cells within the first layout scenario. Embodiments of the present invention are particularly suited to the layout of analog and mixed signal integrated circuits resulting in faster, more flexible, and more efficient layout as compared with conventional techniques which require the layout application to search through a much broader set of possible scenarios.
1. A system for designing an integrated circuit, comprising:
a design engine stored in memory and executable by a processor to:
utilize a cell file library configured to store cell resources comprising composite cell resources;
receive at least one layout constraint;
compile the at least one layout constraint into at least one composite cell implementation;
generate a first layout scenario of one or more geometries in conformance with the at least one composite cell implementation;
generate a second layout scenario in conformance with the first layout scenario, wherein the generation of the second layout scenario comprises generating an open standard compatible cell in conformance with the at least on composite cell implementation and saving the generated open standard compatible cell to a cell file library when a cell in conformance with the first layout scenario does not exist; and
repeat the generation of the second layout scenario until all possible layout scenarios have been exhausted.
2. The system of claim 1 wherein the cell resources further comprise primitive cell resources.
3. The system of claim 1 wherein the cell file library is an open standard compatible file library.
4. The system of claim 1 wherein the composite cell resources comprise meta-cells.
5. The system of claim 1 wherein the cell resources comprise parameterized cells.
6. The system of claim 1 further comprising a network interface configured to communicate with a cell server.
7. The system of claim 1 further comprising a cell server, the cell server comprising the cell file library.
8. A method for designing an integrated circuit, comprising:
receiving at least one layout constraint;
compiling the at least one layout constraint into at least one composite cell implementation, the compiling performed by a processor;
generating a first layout scenario of one or more geometries in conformance with the at least one composite cell implementation;
generating a second layout scenario in conformance with the first layout scenario, wherein the generation of the second layout scenario comprises generating an open standard compatible cell in conformance with the at least on composite cell implementation and saving the generated open standard compatible cell to a cell file library when a cell in conformance with the first layout scenario does not exist; and
repeating the generating of the second layout scenario until all possible layout scenarios have been exhausted.
9. The method of claim 8 further comprising accessing a cell file library.
10. The method of claim 8 , wherein the generating of the second layout scenario comprises retrieving from a cell file library a cell in conformance with at least one composite cell implementation, if one exists.
11. The method of claim 8 , wherein the generating the open standard compatible cell is performed by a composite cell.
12. The method of claim 8 further comprising repeating the generating of the second layout scenario until at least one satisfactory layout scenario has been identified.
13. The method of claim 8 wherein the at least one layout constraint applies to a single cell.
14. The method of claim 8 wherein the at least one layout constraint comprises at least one topological constraint.
15. The method of claim 8 wherein the at least one layout constraint comprises at least one electrical constraint.
16. The method of claim 8 wherein the at least one layout constraint comprises a constraint on the relative coordinates of multiple cells.
17. The method of claim 8 wherein the at least one layout constraint comprises at least one directive.
18. The method of claim 8 wherein the at least one layout constraint comprises at least one design and composition style.
19. A machine readable medium having embodied thereon a program, the program being executable by a machine to perform a method for designing an integrated circuit, the method comprising:
receiving at least one layout constraint;
compiling the at least one layout constraint into at least one composite cell implementation;
generating a first layout scenario of one or more geometries in conformance with the at least one composite cell implementation;
generating a second layout scenario in conformance with the first layout scenario, wherein the generation of the second layout scenario comprises generating an open standard compatible cell in conformance with the at least on composite cell implementation and saving the generated open standard compatible cell to a cell file library when a cell in conformance with the first layout scenario does not exist; and
repeating the generating of the second layout scenario until all possible layout scenarios have been exhausted.