US 2022/0013191 A1Published application

Wafer-yields and write-qos in flash-based solid state drives

AssigneeSK hynix Inc.

InventorsAman Bhatia, Fan Zhang

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Abstract

A non-volatile data storage device includes memory cells arranged in a plurality of blocks and a memory controller coupled to the memory cells for controlling operations of the memory cells. The memory controller is configured to determine if a given block is a bad m-bit multi-level block. In an m-bit multi-level block, each memory cell is an m-bit multi-level cell (MLC), m being an integer equal to or greater than 2. Upon determining that the given block is a good m-bit multi-level block, the memory controller assigns the given block to be an m-bit multi-level user block. Upon determining that the given block is a bad m-bit multi-level block, the memory controller determines if the given block is a good n-bit block. In an n-bit block, each memory cell is an n-bit cell, n being an integer less than m. Upon determining that the given block is a good n-bit block, the memory controller assigns the given block to be an n-bit user block or an n-bit write-buffer block.

Claims20

Dependent claims

A non-volatile data storage device, comprising:

memory cells arranged in a plurality of blocks, each block including multiple pages and each of the multiple pages having a number of memory cells, wherein the plurality of blocks includes:
multi-level user blocks, wherein each memory cell is an m-bit multi-level cell (MLC), m being an integer greater than or equal to 2;
single-level user blocks, wherein each memory cell is a single-bit single-level cell (SLC);
and
single-level write-buffer blocks for improving write operation latency, wherein each memory cell is a one-bit single-level cell (SLC);
and
a memory controller coupled to the memory cells for controlling erase, program, and read operations of the memory cells, wherein the memory controller is configured to:
perform a multi-level test operation to determine if a given block is a bad multi-level block;
upon determining that the given block is a bad multi-level block, perform a single-level test operation to determine if the given block is a good single-level block;
upon determining that the given block is a good single-level block, determine whether the total number of single-level write-buffer blocks exceeds a threshold value;
upon determining that the total number of single-level write-buffer blocks exceeds a threshold value, assign the given block to be a single-level user block;
and
upon determining that the total number of single-level write-buffer blocks does not exceed a threshold value, assign the given block to be a single-level write-buffer block.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/925,158Filed 9 Jul 2020
Published: 13 Jan 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

G11C 29/44
Built-in arrangements for testing, e.g. built-in self testing [BIST] or interconnection details: indication or identification of errors, e.g. for…
G11C 7/02
Arrangements for writing information into, or reading information out from, a digital store: with means for avoiding parasitic signals
G11C 11/5628
Using charge storage in a floating gate: programming or writing circuits; Data input circuits
G11C 11/5671
Using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency: using charge trapping in…