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Patent Searching and Data


Title:
STORAGE DEVICE
Document Type and Number:
Japanese Patent JPH03283095
Kind Code:
A
Abstract:

PURPOSE: To prevent erroneous writing from occurring only in a specified area even when malfunction occurs by noise, etc., by dividing a memory and allocating a write permit signal to each divided memory.

CONSTITUTION: Address signals X0, X1, Y0, and Y1 are decoded by an X decoder 1 and a Y decoder 2. One line is selected respective from X word lines XaWXd and Y word lines YaWYb. Then, arbitrary memories 3 and 4 are chosen. Write permit signals WE1 and WE2 to be impressed from an external terminal, one of address signals, the forward and backward signals of the X1, construct a composite gate 6. The output of this composite gate 6 is turned to 'L' only in the two combination of X1='H' and WE2='H', and X1='L' and WE1='H'. By using this output as a write inhibit signal when it is 'H', the time of X1='H', WE2 is the write permit signal and at the time of X1='L', the WE1 is the write permit signal. Thus, even when the malfunction is generated by the noise or the like, the erroneous writing does not occur only in the specific area.


Inventors:
SATO HIDEKI
Application Number:
JP8277490A
Publication Date:
December 13, 1991
Filing Date:
March 29, 1990
Export Citation:
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Assignee:
NEC CORP
International Classes:
G11C17/00; G11C16/02; G11C16/06; (IPC1-7): G11C16/06
Domestic Patent References:
JPH022435A1990-01-08
JPS63303447A1988-12-12
JPS62165253A1987-07-21
JPS63263697A1988-10-31