Infineon Technologies Ag

Rath Ung

Norbert Rehm

Jan Zieleman

Dirk Fuhrmann

Rob Perry

Robert C Perry

A programmable activate-precharge cycle are provided for a DRAM device. Activate and precharge signals associated with the activate-precharge cycle are generated on the basis of the programmed rate and precharge time with respect to an internal clock of the DRAM device. The activate and precharge signals are coupled to wordlines of the DRAM device, and switched from one wordline to another under internal or external control. One or more functions of the DRAM device are tested while the activate and precharge signals are coupled to wordline. The manner in which switching the activate and precharge signals from one wordline to another wordline is configured depending on the type of testing to be conducted.

Test mode for programming rate and precharge time for DRAM activate-precharge cycle

A random access memory including an array of memory cells configured to store memory cell data, a first circuit, and a second circuit. The first circuit is configured to compare test data and memory cell data to obtain comparison results. The second circuit is configured to compress the comparison results and store the compressed comparison results.

Random access memory including circuit to compress comparison results

Embodiments of the invention generally provide methods and systems for increasing the level of parallelism in testing memory devices. A set of test signals provided by a memory tester may be shared by two or more devices under test. A chip selector may be used to select at least one or all the devices sharing a given set of test signals. By sharing test signals between multiple devices, the level of parallel testing may be increased without increasing the pin count and complexity of memory testers and probe cards.

Test parallelism increase by tester controllable switching of chip select groups

A random access memory including first memory cells, second memory cells, a first voltage source, and a second voltage source. The first voltage source is configured to control the first memory cells. The second voltage source is configured to control the second memory cells. Also, the first voltage source is configured to be trimmed independently of the second voltage source to provide a first voltage that reduces leakage from the first memory cells and the second voltage source is configured to be trimmed independently of the first voltage source to provide a second voltage that reduces leakage from the second memory cells.

Random access memory including first and second voltage sources

A method and apparatus according to the present invention enable wafer chips to be configured with a single power on and off sequence and further enable a chip parameter to be adjusted during a wafer test without utilizing that sequence. In particular, each wafer chip under test is assigned a unique programmable identification. Once each chip has been assigned a corresponding identification, the chips may each be individually accessible by that identification to provide parameter values to chip registers to configure that chip. The configured chips may be subsequently tested in parallel to evaluate the parameter settings. In addition, the present invention enables chips to share data I/O pins or lines, thereby reducing the quantity of testing machine pins utilized for each chip and enabling a greater quantity of chips to be tested in a parallel fashion.

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Apex, NC, United States of America

Rath Ung