Hewlett-packard Development Company, L.p.

Hewlett-packard Company

John R Obermeyer

John F Shelton

Donald A Williamson

A connector for mechanically and electrically connecting devices such that the devices can pivot about two different axes relative to one another.

Connector and apparatus including the same

A system for testing a RAM array bus transaction buffer without halting system operation or using a special protocol, including a RAM control selection circuit for providing to the RAM either a set of normal control, data and address signals or diagnostic control, data and address signals; a Diagnostics Mode Bit Register (DMBR); a Diagnostics Address Register (DAR); and means for recognizing instructions to write to those registers or to a fictitious Diagnostics Data Register (DDR). First a normal write operation is executed to the DMBR, to control a RAM control selection circuit. The RAM control selection circuit chooses as RAM control signal sources a set of diagnostic sources rather than normal system sources. Second, a selected RAM address is written to the DAR. Third, a write operation is performed to the DDR, causing the selected data to be written to the RAM at the address specified by the DAR. Data is similarly read from the RAM through the DDR.

Testable embedded RAM arrays for bus transaction buffering

A scan testable circuit in a computer system is controlled by using a single scan clock and a fixed delay circuit to realize the required scan clocks and a required scan mode enable signal. The multiple signals are generated from a subset of signals supplied to the scan control signal generation circuit. System data and scan data are routed through a multiplexer to test or initialize lines and circuitry. A scan control signal generation circuit according to the invention has the advantage of eliminating as excess a scan mode enable signal originating elsewhere in the computer system, thereby eliminating unneeded signal traces while minimizing the number of pins required for this function. In a first embodiment, a scan mode enable signal is generated from one of two scan clocks. In a second embodiment, both scan clocks and the scan mode enable signal are generated from a single source clock.

Growing community of inventors

Campbell, CA, United States of America

John R Obermeyer