公开(公告)号：JPH0773687A

公开(公告)日：1995-03-17

申请号：JP13431094

申请日：1994-06-16

Applicant: ADVANCED MICRO DEVICES INC

Inventor： JIEEMUZU YUU ,  TEIAO FUO KUO

IPC: G11C17/00 ,  G11C16/06 ,  H03K17/16

Abstract: PURPOSE: To obtain an output buffer circuit programmable using a standard programmer in a high voltage although it is operated with an applied low voltage. CONSTITUTION: A program verifying logic signal from a programmer is detected with the output buffer circuit 10, and the speed of output driver transistors 12, 14 is reduced with a device speed reducing block 11 when the signal is detected. Whereby, a noise problem due to a higher voltage in programming of an EPROM device is excluded, at the same time, the output buffer circuit 10 is operated at a required performance level during the normal operation.

公开(公告)号：JPH0721797A

公开(公告)日：1995-01-24

申请号：JP11995494

申请日：1994-06-01

Applicant: ADVANCED MICRO DEVICES INC

Inventor： JIEEMUZU YUU ,  TEIAOOFUO KUO

IPC: G11C5/14 ,  G11C15/00 ,  G11C15/04 ,  G11C16/06 ,  G11C16/30 ,  G11C17/00 ,  G11C29/00 ,  G11C29/04

Abstract: PURPOSE: To correctly operate an associative memory device in both of reading- out and program modes by changing over the first and second bias voltages applied to this device by a selector switch according to the detection results of the first and second source voltages supplied to the device. CONSTITUTION: The respective detecting circuits 48 or 50 and 60 output signals 49, 52, 62 when these circuits detect the source voltages Vcc or Vpp , in both reading-out and programming modes of the EPROM of the associative memory device. The sure and adequate operation of both modes is executed by a latch 14 and the spare columns and rows 30 and 32 of a ROM 18 are exactly addressed by the reset signal 42 outputted from an OR gate 64 by these signals. The switch 58 selects the adequate bias voltage 54 or 56 for both modes to be inputted and outputs the voltages to a UPROM 12 by the signal 52. As a result, the ROM 18 is programmed by the low source voltage, by which power source consumption is reduced. The ROM is operated by the high voltage during the programming. The correct operation is thus executed at multiple power source levels.