Erasable programmable read-only memories

GPHYSICS G11Information storage G11CSTATIC STORES

G11C16/00Erasable programmable read-only memories

G11C16/02electrically programmable G11C16/04using variable threshold transistors G11C16/0408comprising cells containing floating gate transistors G11C16/0416comprising cells containing a single floating gate transistor and no select transistor G11C16/0425comprising cells containing a merged floating gate and select transistor G11C16/0433comprising cells containing a single floating gate transistor and one or more separate select transistors G11C16/0441comprising cells containing multiple floating gate devices G11C16/045Floating gate memory cells with both P and N channel memory transistors, usually sharing a common floating gate G11C16/0458comprising plural independent floating gates which store independent data G11C16/0466comprising cells with charge storage in an insulating layer G11C16/0475comprising plural independent storage sites which store independent data G11C16/0483comprising cells having several storage transistors connected in series G11C16/0491Virtual ground arrays G11C16/06Auxiliary circuits G11C16/08Address circuits Decoders Word-line control circuits G11C16/10Programming or data input circuits G11C16/102External programming circuits G11C16/105Circuits or methods for updating contents of nonvolatile memory, especially with 'security' features to ensure reliable replacement G11C16/107Programming all cells in an array, sector or block to the same state prior to flash erasing G11C16/12Programming voltage switching circuits G11C16/14Circuits for erasing electrically G11C16/16for erasing blocks G11C16/18Circuits for erasing optically G11C16/20Initialising Data preset Chip identification G11C16/22Safety or protection circuits preventing unauthorised or accidental access to memory cells G11C16/225Preventing erasure, programming or reading when power supply voltages are outside the required ranges G11C16/24Bit-line control circuits G11C16/26Sensing or reading circuits Data output circuits G11C16/28using differential sensing or reference cells G11C16/30Power supply circuits G11C16/32Timing circuits G11C16/34Determination of programming status G11C16/3404Convergence or correction of memory cell threshold voltages; Repair or recovery of overerased or overprogrammed cells G11C16/3409Circuits or methods to recover overerased nonvolatile memory cells detected during erase verification, usually by means of a "soft" programming step G11C16/3413Circuits or methods to recover overprogrammed nonvolatile memory cells detected during program verification, usually by means of a "soft" erasing step G11C16/3418Disturbance prevention or evaluation; Refreshing of disturbed memory data G11C16/3422Circuits or methods to evaluate read or write disturbance in nonvolatile memory, without steps to mitigate the problem G11C16/3427Circuits or methods to prevent or reduce disturbance of the state of a memory cell when neighbouring cells are read or written G11C16/3431Circuits or methods to detect disturbed nonvolatile memory cells G11C16/3436Arrangements for verifying correct programming or erasure G11C16/344Arrangements for verifying correct erasure or for detecting overerased cells G11C16/3445Circuits or methods to verify correct erasure of nonvolatile memory cells G11C16/345Circuits or methods to detect overerased nonvolatile memory cells, usually during erasure verification G11C16/3454Arrangements for verifying correct programming or for detecting overprogrammed cells G11C16/3459Circuits or methods to verify correct programming of nonvolatile memory cells G11C16/3463Circuits or methods to detect overprogrammed nonvolatile memory cells, usually during program verification G11C16/3468Prevention of overerasure or overprogramming G11C16/3472Circuits or methods to verify correct erasure of nonvolatile memory cells whilst erasing is in progress G11C16/3477Circuits or methods to prevent overerasing of nonvolatile memory cells G11C16/3481Circuits or methods to verify correct programming of nonvolatile memory cells whilst programming is in progress G11C16/3486Circuits or methods to prevent overprogramming of nonvolatile memory cells G11C16/349Arrangements for evaluating degradation, retention or wearout G11C16/3495Circuits or methods to detect or delay wearout of nonvolatile EPROM or EEPROM memory devices