Methods and Devices For Reading Data From Non-Volatile Memory Cells
AssigneeCypress Semiconductor Corporation
InventorsKobi Danon, Yoram Betser, Alex Kushnarenko
Life of this patent
Estimating the term…
Abstract
Disclosed is a method for responding to a single user read command of a complementary cell array including one or more complementary cell pairs, the method including: determining if a first group of cells out of a data word is in an erased state or in a programmed state, and outputting a data word so that (a) if the first group of cells is determined to be erased a logical “one” is output for each bit of the data word and (b) if the first group of cells is determined to be programmed the result of a complementary read is output for each bit of the data word.
Claims21
1-19. (canceled)
A method, comprising:
- obtaining a memory device including N complementary memory cells, each complementary memory cell including a first and a second memory cells, wherein N is a natural number greater than 0, and wherein the memory device stores a threshold number that is pre-defined initially and programmable subsequently;
- determining if each of the first memory cells of the N complementary memory cells is in a first binary state or a second binary state;
- determining if each of the second memory cells of the N complementary memory cells is in the first binary state or the second binary state;
- generating a count value by counting a total number of the first and second memory cells that are in the first binary state;
- and
- determining if the N complementary memory cells are programmed based on a result of comparing the count value to the threshold number.
A memory device, comprising:
- a plurality of complementary memory cells, each including a bit cell and a complementary cell;
- a plurality of sense amplifiers configured to compare output of the bit and complementary cells to a reference signal;
- a binary state counter coupled to the plurality of sense amplifiers, configured to generate a count number corresponding to a cumulative number of the bit and complementary cells that include output less than the reference signal, wherein the binary state counter is further configured to generate a state indicator based on a comparison between the count number and a state-parameter threshold number that is pre-determined initially, wherein the state-parameter threshold number is configured to be programmable and adjustable throughout a life of the memory device;
- a plurality of multiplexors, wherein each multiplexor is configured to be coupled to a differential sensing result of one of the plurality of complementary memory cells and an erased binary state signal, each multiplexor is further configured to be coupled to the state indicator as a control signal.
A non-transitory computer readable storage medium comprising stored instructions thereon, the instructions when executed cause a processing element to:
- execute a read command of N memory cells of a memory device, wherein N is a natural number greater than 0, and each memory cell includes a bit cell and a complementary cell, the read command further includes,
- a first read event wherein output of each of the bit cells is compared to a reference signal, and
- a second read event wherein output of each of the complementary cells is compared to the reference signal;
- generate a cumulative count value corresponding to results of the first and second read events;
- compare the cumulative count value to a threshold value to determine if the N memory cells are in a programmed state, wherein the threshold value is pre-determined initially and programmable;
- and
- output results of differential sensing of each memory cell when the N memory cells are determined in the programmed state.
Dependencies are inferred from the claim text.