Browse Prior Art Database

Memory Array having Independent Data Reading and Data Checking

IP.com Disclosure Number: IPCOM000077061D
Original Publication Date: 1972-Jun-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

DasGupta, S: AUTHOR

Abstract

Data is read from memory arrays in order to retrieve the stored data as well as to check the proper functioning of the array. The capability is desirable that the reading of the stored data for the aforementioned independent purposes be accomplishable at mutually independent times, without interference and without requiring extensive additional circuit provision.

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Memory Array having Independent Data Reading and Data Checking

Data is read from memory arrays in order to retrieve the stored data as well as to check the proper functioning of the array. The capability is desirable that the reading of the stored data for the aforementioned independent purposes be accomplishable at mutually independent times, without interference and without requiring extensive additional circuit provision.

Every word in the array represented in the figure can be checked for single errors and read at the same or different times without interference. The figure shows four representative cells of a memory array provided with the usual Sit lines 1, 2, 1' and 2' and read word lines 3 and 4. To these are added check word lines 5 and 6, check read lines 7 and 7' and an extra transistor per memory cell (transistors 8, 9, 10 and 11) to read the contents out of each cell for a check operation. Checking is accomplished by using those sides of the memory cells which are not used for normal data retrieval operations. In this manner, the checking function is maintained separate from the usual search-read operation in the array.

Word selector 12 lowers the potential at the base of transistor 13 when it is desired to check the word including storage cells 14 and 15. Check word line 5 is lowered enabling transistors 8 and 9 to conduct in the event that nodes A and A' also are up, denoting that a zero is stored in the respective bistable cells. The conduction of tran...