Data Storage and Replay Apparatus

• US 20090150748A1
• Filed: 07/22/2005
• Published: 06/11/2009
• Est. Priority Date: 08/02/2004
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Egner, Sebastian, Blum, Martinus W., Lambert, Nicolaas, Van Acht, Victor M. G., Tolhuizen, Ludovicus M. G. M.
• Granted Patent: US 8,402,325 B2
• Time in Patent Office: Days
• US Class Current: 714/758
• CPC Class Codes: G06F 11/1012 using codes or arrangements adapted for a specific type of error G06F11/1048 takes precedence
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: H03M 13/35 Unequal or adaptive error protection, e.g. by providing a different level of protection according to significance of source information or by adapting the coding according to the change of transmission channel characteristics

Abstract

A data storage and replay device uses measurements of the evolution of performance of the storage medium (typically a flash memory circuit) to predict an error rate of retrieval from a region of the storage medium. The prediction is used as a basis for dynamically selecting an ECC for encoding the data prior to storage of the data. The ECC is selected from a plurality of available ECC'"'"'s so that a fastest encodable ECC is selected that is predicted to produce no more than a predetermined post-decoding error rate given said information. In this way the speed of transmission of data to the device can be maximized while keeping the error rate below an acceptable level in the predicted future after decoding. On decoding the data, which is typically audio or video data, is decoded and replayed at a predetermined speed. In another embodiment, the data stored using a plurality of ECC'"'"'s together and an ECC is selected dynamically for decoding, so that an output data rate can be maximized or power consumption on replay can be minimized.

Claims

1. A data storage and replay device, comprising

a storage medium;

an error rate assessment unit arranged to generate information about a prediction of an error rate of retrieval from a region of the storage medium based on measurements of performance of the storage medium during use;

an encoder for performing encoding of received data into an ECC before storage of the encoded received data into the region, the encoder selecting the ECC adaptively dependent on said information from the error rate assessment unit.

2. A data storage and replay device according to claim 1, having an input circuit that is arranged to adapt a rate of reception of the received data dependent on the selected ECC.

3. A data storage and replay device according to claim 1, wherein the ECC is selected from a plurality of available ECC'"'"'s so that a fastest encodable ECC is selected that is predicted to produce no more than a predetermined post-decoding error rate given said information.

4. A data storage and replay device according to claim 1, comprising a decoder circuit arranged to read the data from said region as well as information that is indicative of the selected ECC for the region and to decode the data from the region according to the indicated ECC.

5. A data storage and replay device according to claim 4, having an output for outputting decoded data at least at a predetermined replay rate for use in audio and/or video replay.

6. A data storage and replay device according to claim 1, wherein the storage medium comprises a plurality of regions, the error rate assessment unit assessing respective information for respective ones of the regions, the encoder selecting the ECC for each region particular dependent on the information for the particular region.

7. A data storage and replay device according to claim 1, wherein the storage medium is a flash memory circuit.

8. A data storage and transmission device, comprising

a storage medium;

an error rate assessment unit, arranged to generate information about a prediction of an error rate of retrieval from a region of the storage medium based on measurements of performance of the storage medium during use;

a decoder for performing decoding of data, which is retrieved from a region of the storage medium, according to an ECC, the decoder selecting the ECC from a plurality of available ECC'"'"'s dependent on said information from the error rate assessment unit.

9. A data storage and transmission device according to claim 8, having an output circuit that is arranged to adapt a rate of transmission of the retrieved and decoded data dependent on the selected ECC.

10. A data storage and transmission device according to claim 8, comprising an encoder circuit arranged to store the data initially encoded according to a selected one of the ECCs, which is selected adaptively dependent on said information from the error rate assessment unit.

11. A data storage and transmission device according to claim 8, comprising an encoder circuit arranged to store the data for retrieval and decoding so that the same data is encoded according to all of said plurality of ECCs.

12. A data storage and transmission device according to claim 8, wherein the storage medium is a flash memory circuit.

13. A method of writing data into a storage medium the method comprising

gathering measurements of performance of the storage medium during use;

generating information about a prediction of an error rate of retrieval from a region of the storage medium based on the measurements;

selecting an ECC from a plurality of ECC that are supported by an encoder the selection being adaptive in response to the generated information,

encoding received data into the selected ECC with the encoder before storage of the encoded received data into the region.

15. A computer program product comprising machine instructions which, when loaded into a programmable computer make the computer perform the method according to claim 13.

14. A method of reading data from a storage medium, the method comprising

gathering measurements of performance of the storage medium during use;

generating information about a prediction of an error rate of retrieval from a region of the storage medium based on the measurements;

selecting an ECC from a plurality of ECC that are supported by a decoder the selection being adaptive in response to the generated information,

decoding received data with the decoder according to the selected ECC before storage of the encoded received data into the region.