# US 6,297,988 B1 · Mode indicator for multi-level memory

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 6,297,988 B1
- Document ID: US6297988B1
- Status: Granted
- Kind: B1
- Application number: 09/513,402
- Filed: 2000-02-25
- Granted: 2001-10-02
- Earliest claimed: 2000-02-25
- Assignees: Advanced Micro Devices, Inc.
- Inventors: Allan Parker; Joseph Kucera
- Web page: https://patentgrep.com/patent/US6297988B1

## CPC

- G11C 11/5621: {using charge storage in a floating gate}
- G11C 2211/5641: Multilevel memory having cells with different number of storage levels
- G11C: STATIC STORES (semiconductor memory devices H10B)

## Abstract

A memory device having a plurality of memory cells that are group into at least two group of cells. Each cell is capable of being programmed in at least two modes. A mode indicator is associated with each group of cells. The mode indicator indicates which programming mode is used to access the cells. The mode indicator is one or more bits and optionally is user selectable.

## Claims

### Claim 1

A memory device, comprising:
(a) a plurality of memory cells comprising at least a first and second group of cells, each cell being capable of being programmed in a plurality of programming modes; and
(b) a first mode indicator associated with the first group of cells, and a second mode indicator associated with the second group of cells each mode indicator being part of the same memory as the first and second groups of memory cells and being capable of indicating one of the plurality of program modes.

### Claim 2 (depends on 1)

The memory device of claim 1, wherein the mode indicator is a single bit.

### Claim 3 (depends on 1)

The memory device of claim 1, wherein the mode indicator is user programmable.

### Claim 4 (depends on 1)

The memory device of claim 1, wherein the mode indicator is user selectable.

### Claim 5 (depends on 1)

The memory device of claim 1, wherein the first and second mode indicators are stored in a mode indicator memory.

### Claim 6 (depends on 1)

The memory device of claim 1, wherein the first and second group of cells include a first and second page of cells, respectively.

### Claim 7 (depends on 6)

The memory device of claim 6, wherein the first and second pages of cells each include at least 4096 cells.

### Claim 8 (depends on 1)

The memory device of claim 1, wherein the plurality of modes includes a first mode and a second mode, the first mode being a single bit mode and the second mode being a multi-level mode.

### Claim 9 (depends on 8)

The memory device of claim 8, wherein the multi-level mode includes a first, second, third, and fourth programming level and the single bit mode includes a fifth and sixth programming level, the fifth and six programming levels being approximately equal to two of the first, second, third, and fourth programming levels.

### Claim 10 (depends on 8)

The memory device of claim 8, wherein the mode indicator defaults to the single bit mode.

### Claim 11

A method of accessing multi-bit memory cells, comprising:
(a) determining a first mode value from a first mode indicator, the first mode indicator being associated with a first segment of the multi-bit memory cells, the first mode indicator being capable of indicating at least a first and second mode and being part of the same memory thereof, the first mode comprising single bit access and the second mode comprising multi-bit access; and
(b) accessing the first segment of multi-bit cells using an access mode corresponding to the first mode value.

### Claim 12 (depends on 11)

The method of claim 11, further including:
(c) determining a second mode value from a second mode indicator, the second mode indicator being associated with a second segment of the multi-bit memory cells, the second mode indicator being capable of indicating at least a first and second mode, the first mode comprising single bit access and the second mode comprising multi-bit access; and
(d) accessing the second segment of multi-bit cells using an access mode corresponding to the second mode value.

### Claim 13 (depends on 12)

The method of claim 12, wherein the first and second segment of multi-bit memory cells are unique.

### Claim 14 (depends on 11)

The method of claim 11, wherein said determining a first mode value comprises reading the first mode value from the first mode indicator.

### Claim 15 (depends on 11)

The method of claim 11, wherein said accessing the first segment comprises reading data from the first segment of multi-bit memory cells.

### Claim 16 (depends on 11)

The method of claim 11, wherein said accessing the first segment comprises writing data to the first segment of multi-bit memory cells.

### Claim 17

A memory device, comprising:
(a) a storage means for storing data capable of storing data in a plurality of storage formats;
(b) an indication means for indicating which of the plurality of different formats is to be used to access the data, said indication means being part of the same memory as said storage means; and
(c) an accessing means for accessing the data stored in the storage means.

### Claim 18 (depends on 17)

The memory device of claim 17, wherein the plurality of storage formats includes a single-bit and a multi-bit format.

### Claim 19 (depends on 17)

The memory device of claim 17, wherein the storage means includes a plurality of storage areas and the indicator means includes a separate indicator for each storage area.

### Claim 20 (depends on 19)

The memory device of claim 19, wherein each storage area is a page of memory.