Siemens Aktiengesellschaft

Gerhard Grassl

Hans-Joerg Pfleiderer

A function check of a programmable logic array is performed in which input lines, product term lines and ground lines are combined into an AND plane and output lines, product term lines and ground lines are combined into an OR plane. The aim is a simple method of function check which permits any potentially-existing fault to be detected. The check is achieved by generating, with a test data generator, bit patterns and applying the same to the input lines, and, through the use of a shift register, successively sensitizing the product term lines either individually or in groups, i.e. disconnecting the same from ground potential. The bit patterns occurring at the output lines are supplied to a test data evaluator. The area of use is in logic circuitry of data processing technology.

Method and arrangement for an operational check of a programmable logic

A semiconductor storage circuit has a plurality of storage elements which are provided with storage capacitors and which are grouped in rows and columns and integrated on a doped semiconductor body. The storage elements which form a row are provided with a common first drive line and the storage elements which form a column are provided with a second common drive line. The first drive lines are formed from strip-like electrically conductive layers which are separated by an insulating layer from the surface of the semiconductor body and the second drive lines consist of buried lines which extend within the semiconductor body and are oppositely doped with respect to the body. The insulating layer is designed to be thinner within the intersection zones of the drive lines so that in these zones insulating layer capacitors are formed which possess outer electrodes composed of parts of the first drive lines and which represent storage capacitors of the storage elements. The widths of the buried lines which represent the second drive lines are designed to be less than the dimensions, oriented transversely to these strips, of the outer electrodes, and between the buried lines which represent the second drive lines further buried lines are arranged which can be connected by way of terminals to a voltage source.

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Munich, Germany

Gerhard Grassl