Multi-purpose non-volatile memory card

• US 7,554,842 B2
• Filed: 07/06/2004
• Issued: 06/30/2009
• Est. Priority Date: 09/17/2001
• Status: Expired due to Term

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Corporation (Western Digital Corporation)
• Inventors: Barzilai, Ron, Elhamias, Reuven
• Primary Examiner(s): NGUYEN, TAN
• Application Number:
  US10/886,302
• Publication Number:
  US 20050007801A1
• Time in Patent Office: 1,820 Days
• Field of Search: 365/185.01, 365/168
• US Class Current: 365/185.03
• CPC Class Codes: G11C 11/56 using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: G11C 11/5621 using charge storage in a floating gate
• CPC Class Codes: G11C 11/5628 Programming or writing circuits; Data input circuits
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/12 Programming voltage switching circuits
• CPC Class Codes: G11C 2211/5641 Multilevel memory having cells with different number of storage levels

Abstract

A flash non-volatile memory system that normally operates its memory cells in multiple storage states is provided with the ability to operate some selected or all of its memory cell blocks in two states instead. The two states are selected to be the furthest separated of the multiple states, thereby providing an increased margin during two state operation. This allows faster programming and a longer operational life of the memory cells being operated in two states when it is more desirable to have these advantages than the increased density of data storage that multi-state operation provides. An exemplary embodiment is as a memory card where the user can choice between two state and multi-state operation.

Claims

1. An electronic circuit card connectable to a host for the transfer of data and commands therebetween, comprising:

a non-volatile memory comprising a plurality of storage elements operable in either a binary mode, wherein each of the storage elements stores one of exactly two data states, or in a multi-state mode, wherein each of the storage elements stores more than two data states; and

a controller to manage the storage and access of data in the memory, wherein, in response to a command from external to the card, the memory is managed in the binary or the multi-state mode, wherein the controller manages the storage and access of data in the memory according to a first firmware file for the binary mode and a second firmware file for the multi-state mode.

2. The electronic circuit card of claim 1, wherein the external command is initiated prior to the storage of said data by user of a host to which the card is connected and wherein one of said first and second firmware files is downloaded by the controller from the host in response to the external command.

3. The electronic circuit card of claim 2, wherein a configuration file that defines said one of said first and second firmware files is also downloaded by the controller from the host in response to the external command.

4. A method of operating an electronic circuit card including a non-volatile memory operable in a plurality of data storage modes having differing operational characteristics, the method comprising:

attaching the card to a host;

in response to said attaching, transmitting a mode selection request from the card to the host;

selecting by a user of the host from the operational characteristics in response to the mode selection request;

transmitting the user'"'"'s mode selection from the host to the card;

transferring data from the host to the card and storing the data therein according to the selected data storage mode corresponding to the selected operational characteristics.

5. The method of claims 4, wherein the operational characteristics include relative capacity of the non-volatile memory.

6. The method of claims 4, wherein the operational characteristics include relative speed of said transferring data.

7. The method of claim 4 further comprising:

in response to transferring to said selecting and prior to said transferring data, transferring a firmware file from the host to the card for the operation of the card according to the selected data storage mode.

8. The method of claim 7 further comprising:

in response to transferring to said selecting and prior to said transferring data, transferring a configuration file defining said transferred firmware file card operational characteristics from the host to the card.