Hewlett-Packard Company

Hewlett-Packard Development Company, L.p.

Rambus Inc.

Joseph H Hassoun

William R Bryg

Sorin Iacobovici

James A Gasbarro

A linked list structure in a computing system includes a first entry and additional entries. Each additional entry includes a link reference to a prior entry in the linked list. The link reference for each additional entry all are stored within a content addressable memory. Each additional entry is accessible by performing a content search using the link reference to the prior entry. The linked list is traversed by accessing the first entry in the linked list. A second entry in the linked list is accessed by searching the content addressable memory with an index of the first entry. A third entry in the linked list is accessed by searching the content addressable memory with an index of the second entry.

Forming linked lists using content addressable memory

A test device for an integrated circuit utilizes current mode test signal shaping to evaluate circuit performance within at least one selected voltage swing. An interface circuit has an output line that is coupled to the integrated circuit under test. An upper voltage level (V.sub.OH) is established by a connection of the output line to a voltage source. The connection to the source includes a resistor. Parallel switchable current paths to a voltage level significantly less than V.sub.OH are also formed from the output line. In the preferred embodiment, the current paths are MOS transistors to electrical ground. The transistors in an 'on' state act as current sinks that create a greater voltage drop across the resistor. Consequently, there is a correspondence between the number of transistors that are switched by input of a test signal and the difference between V.sub.OH and V.sub.OL. In the preferred embodiment, the interface circuit is used in the testing of a memory circuit, such as DRAM. Test sequences can be executed at different levels of V.sub.OH and V.sub.OL, thereby ensuring that the integrated circuit under test will operate properly under different potential conditions.

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Pleasanton, CA, United States of America

Joseph H Hassoun