SEMICONDUCTOR INTEGRATED CIRCUIT FOR TELEPHONE SET

PURPOSE:To increase a memory protection voltage more by devising the circuit such that a redial memory or a memory cell and an input output of a repertory memory is driven at a voltage lower than a power supply voltage. CONSTITUTION:At memory readout, one of bit lines 3 is selected and an H level is...

Full description

Saved in:
Bibliographic Details
Main Author OGASAWARA YASUAKI
Format Patent
LanguageEnglish
Published 27.09.1991
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
INFORMATION STORAGE
PHYSICS
STATIC STORES
TELEPHONIC COMMUNICATION
Online AccessGet full text

Cover

More Information
Summary:PURPOSE:To increase a memory protection voltage more by devising the circuit such that a redial memory or a memory cell and an input output of a repertory memory is driven at a voltage lower than a power supply voltage. CONSTITUTION:At memory readout, one of bit lines 3 is selected and an H level is shifted to VDD level or VSSC level by a level shifter 4 and a signal is inputted to a RAM 5 driven at the VSSC level. Similarly, a level of a word line 6 is brought from an H level into the VDD level or VSSC level by a level shifter 7 and the signal is inputted to the RAM 5. An output 8 from the RAM 5 is shifted from H level into the VSSC or VDD level by a level shifter 9. Thus, a redial memory or a memory cell and an input/output of a repertory memory 5 is driven at a voltage level VSSC lower than a power supply voltage level VDD to increase the memory protection voltage more.
Bibliography:Application Number: JP19890246131