Research on OR logic operation based on NOR memristor memory array

Abstract Test engineers and failure analyst familiar with random access memory arrays have probably encountered the frustration of dealing with address descrambling. The resulting nonsequential internal bit cell counting scheme often means that the location of the failing cell under investigation is nowhere near where it is expected to be. A logical to physical algorithm for decoding the standard library block might have been provided with the design, but is it still correct now that the array has been halved and inverted to fit the available space in a new processor chip? Off-line labs have traditionally been tasked with array layout verification. In the past, hard and soft failures could be induced on the frontside of finished product, then bitmapped to see if the sites were in agreement. As density tightened, flip-chip FIB techniques to induce a pattern of hard fails on packaged devices came into practice. While the backside FIB edit method is effective, it is complex and expensive. The installation of an in-line Dual Beam FIB created new opportunities to move FA tasks out of the lab and into the FAB. Using a new edit procedure, selected wafers have an extensive pattern of defects 'written' directly into the memory array at an early process level. Bitmapping of the RAM blocks upon wafer completion is then used to verify correlation between the physical damaged cells and the logical sites called out in the test results. This early feedback in-line methodology has worked so well that it has almost entirely displaced the complex laboratory procedure of backside FIB memory array descramble verification.

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Military Specification, Modules, Standard Electronic Memory Array, 128K Dynamic Random Access Module, Key Code JEJ

10.21236/ada347026 ◽

1991 ◽

Author(s):

NAVAL SEA SYSTEMS COMMAND WASHINGTON DC

Keyword(s):

Random Access ◽

Memory Array

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Hierarchical mechanical metamaterials built with scalable tristable elements for ternary logic operation and amplitude modulation

Science Advances ◽

10.1126/sciadv.abf1966 ◽

2021 ◽

Vol 7 (9) ◽

pp. eabf1966

Author(s):

Hang Zhang ◽

Jun Wu ◽

Daining Fang ◽

Yihui Zhang

Keyword(s):

Structural Diversity ◽

Cell Number ◽

Structural Elements ◽

Ternary Logic ◽

Stable States ◽

One Dimensional ◽

Logic Operation ◽

Artificial Materials ◽

Mechanical Metamaterials ◽

Unit Cells

Multistable mechanical metamaterials are artificial materials whose microarchitectures offer more than two different stable configurations. Existing multistable mechanical metamaterials mainly rely on origami/kirigami-inspired designs, snap-through instability, and microstructured soft mechanisms, with mostly bistable fundamental unit cells. Scalable, tristable structural elements that can be built up to form mechanical metamaterials with an extremely large number of programmable stable configurations remains illusive. Here, we harness the elastic tensile/compressive asymmetry of kirigami microstructures to design a class of scalable X-shaped tristable structures. Using these structure as building block elements, hierarchical mechanical metamaterials with one-dimensional (1D) cylindrical geometries, 2D square lattices, and 3D cubic/octahedral lattices are designed and demonstrated, with capabilities of torsional multistability or independent controlled multidirectional multistability. The number of stable states increases exponentially with the cell number of mechanical metamaterials. The versatile multistability and structural diversity allow demonstrative applications in mechanical ternary logic operators and amplitude modulators with unusual functionalities.

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