Browse Prior Art Database

Block Erase for One Device Cell Memory Arrays

IP.com Disclosure Number: IPCOM000089226D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Gray, KS: AUTHOR [+3]

Abstract

A block erase is provided by writing one polarity of data into multiple cells in one write cycle in memory arrays utilizing cells, each having a single field-effect transistor and a storage capacitor, as described more fully in U. S. Patent 3,387,286.

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Block Erase for One Device Cell Memory Arrays

A block erase is provided by writing one polarity of data into multiple cells in one write cycle in memory arrays utilizing cells, each having a single field-effect transistor and a storage capacitor, as described more fully in U. S. Patent 3,387,286.

In the array of one-device cells, a cell such as cell A of Fig. 1 is coupled to a bit line, e. g., the left bit line which is connected to a sense latch. A right bit line may also be connected to this sense latch with a cell B coupled to the right bit line. Although only cells A and B are shown as connected to the left and right bit lines, respectively, in practice each of these bit lines has numerous such cells coupled thereto.

In order to block erase the cells in the array indicated in Fig. 1, a block erase pulse, as shown in Fig. 2, is applied to the gate electrode of field-effect transistor T1, which connects the left bit line to ground, causing a cell, such as cell A, connected to the left bit line to store one polarity of information, for example, 0. The word line and the block erase line are connected to similar cells and transistors T1 coupled to other left bit lines of the memory array; consequently, an entire word line of cells can be block erased in one cycle. The time t1 between the start of the block erase pulse and the word line pulse should be equal to or greater than zero. Since the block erase pulse causes the cells coupled to the left bit line to store...