Place-holding library elements for defining routing paths
US6308309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1999 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | Aug 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/903
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Described is a method of using place-holding cells, or "stopper cells," to force a place-and-route tool to route a selected signal path through a particular physical location on a semiconductor die. In one method, phantom blocks, created from the design specification, define the area, logic, timing, and the placement of input/output (I/O) ports for a number of custom blocks. These phantom blocks are combined with any standard blocks to create a high-level description of a desired circuit. Then, for each I/O port of the custom blocks, a place-holding cell, or "stopper cell," is added to the description in the path defined between the I/O port and its source or destination. The stopper cells are then grouped with the associated custom blocks and the resulting collection of stopper cells and blocks are placed and routed. Completed custom blocks can then be substituted for respective phantom blocks after place and route. Stopper cells preserve complex routing during this substitution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.