Yuncheng F Yu

US Patent:

60186224, Jan 25, 2000

Filed:

Sep 24, 1997

Appl. No.:

8/936647

Inventors:

Arthur Lin - San Jose CA
Kui K. Yau - Saratoga CA
Yuncheng F. Yu - Palo Alto CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G06F 1750

US Classification:

39550003

Abstract:

In a control block design methodology, a control block is designed, synthesized, and laid out. The control block includes one or more storage devices, such as flops. The flops include a header which buffers signals common to the flops and a storage cell for storing data. A flop grouping tool is used to merge flops having the same type of header into a flop having storage equivalent to the merged flops but using a single header. Multiple instances of the header may be deleted from the control block.

US Patent:

59833769, Nov 9, 1999

Filed:

Sep 24, 1997

Appl. No.:

8/935470

Inventors:

Sridhar Narayanan - Sunnyvale CA
Yuncheng F. Yu - Palo Alto CA
Arthur Lin - San Jose CA
Hongyu Li - Hayward CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G01R 3128

US Classification:

714726

Abstract:

In a control block design methodology, control block design proceeds without the inclusion of scan functionality until the functional design specifications are met. After meeting the functional design specifications, a scan insertion tool is executed to automatically insert scan functionality. The insertion is performed in such a manner that the functional cells within the control block are not perturbed. Therefore, functional timing may be minimally affected, if at all. In one embodiment, a scan enable buffer is inserted at the end of each row in the control block. Flops (or other scannable storage devices) within the row are connected to the scan enable line provided by the scan enable buffer within the row. Additionally, flops are connected into a scan chain on a row-by-row basis, minimizing the length of the wires connecting the scan chain. If a particular scan chain wire exceeds a length which will meet scan timing requirements, a scan chain buffer can be inserted as well (e. g.