Method for placement-based scan-in and scan-out ports selection
US6405355B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1999 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Mar 31, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318594
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A computer implemented method of constructing a scan chain. According to the present invention, scan cells are inserted into a netlist description of an integrated circuit design and are coupled serially together to form a scan chain. The resulting netlist is then passed to layout processes where the cells of the integrated circuit design are automatically placed and routed. The layout processes are performed without regard to any predetermined constraints designating any particular functional pins of the netlist design as scan-in or scan-out ports for the scan chain. After the cells are placed, a first functional pin is selected as the scan-in port and a second functional pin is selected as the scan-out port according to cell placement information. In particular, the functional pin that is closest to the leading scan cell is selected as the scan-in port. The functional pin that is closest to the last scan cell is selected as the scan-out port for the scan chain. Scan-in functionalities are then added to the first functional pin and scan-out functionalities are added to the second functional pin. The present invention thereby improves cell placement and wire routability, and allows…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.