International Business Machines Corporation

Peter Mannherz

Norbert Schumacher

Ingemar Holm

Helmut Kohler

Gerhard Zilles

Peter Rudolph

Dietrich W Bock

Hermann Schulze-Scholling

A circuit for checking the memory array address and contents is described. The circuit consists of at least one write address counter (120) and at least one read address counter (130). Before a data word is read into the array, each of its check bits are XORed with one bit of the address location at which the word is to be written. On reading out the word, the check bits are again XORed with the bits of the address location to restore their original value and the parity of the data word is checked. If the parity is found to be incorrect then it is known that an error has occurred either on reading in or reading out and the appropriate action can be taken.

Method and apparatus for checking the address and contents of a memory

In computer systems deliberate initializations/resets of the processor latches which represent the internal processor states are necessary to erase only such information which is not required for a subsequent operation, e.g., processing/logging error data, prior to a processor start. One or more reset areas are defined which are initialized/reset in a staggered mode, where in each area a group of latches is assembled which have to be initialized/reset depending on the cause, e.g., power-on, for such a system initialization/reset. The latches within a reset area are connected to form shift registers which are initialized/reset by propagating a binary zero through all latches of the area(s) to be reset.

Arrangement in a self-guarding data processing system for system

Growing community of inventors

Schoenaich, Germany

Peter Mannherz