Semiconductor memory device

Patent metadata

Field	Value
Publication number	US-2016266973-A1
Application number	US-201615061487-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Mar 12, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

According to one embodiment, a semiconductor memory device includes an encoder configured to generate an error correction code with respect to data, a processor configured to perform interleaving with respect to the data output from the encoder after the generation of the error correction code by the encoder, and a memory configured to store a process result from the processor.

First claim

What is claimed is:

1 . A semiconductor memory device comprising:
an encoder configured to generate an error correction code with respect to data; a first processor configured to perform interleaving with respect to the data from the encoder after the generation of the error correction code; a memory configured to store a process result from the first processor; a detector configured to detect a credibility value indicative of credibility of the data read from the memory; and a controller configured to determine whether or not the credibility value of the data read from a predetermined area of the memory is equal to or greater than a predetermined value based on a detection result from the detector, the controller configured to perform the interleaving with respect to the data read from the predetermined area if the credibility value is equal to or greater than the predetermined value and to withhold the interleaving with respect to the data read from the predetermined area if the credibility value is less than the predetermined value.

2 . The semiconductor memory device of claim 1 , wherein the credibility value is an error rate per unit time of the data read from the predetermined area.

3 . The semiconductor memory device of claim 2 , wherein the predetermined value is used to determine whether or not a burst error occurs.

4 . The semiconductor memory device of claim 2 , wherein the controller performs the determination using the error rate per unit time of the data, and in addition thereto, at least one of the number of writes to the memory, refresh time interval, and integral value derived from a temperature inside the semiconductor memory device and a retaining time of the temperature.

5 . The semiconductor memory device of claim 1 , wherein the interleaving includes the number of paths and delay unit as parameters, and the controller changes the number of paths and the delay unit depending on the credibility value.

6 . The semiconductor memory device of claim 1 , further comprising a decoder configured to decode the encoded data read from the memory.

7 . The semiconductor memory device of claim 6 , further comprising a second processor configured to perform deinterleaving with respect to the encoded data before the decoder performs decoding.

8 . The semiconductor memory device of claim 1 , wherein the encoder includes a code length and parity as parameters, and the controller changes the parity length depending on a change in the code length.

9 . The semiconductor memory device of claim 8 , wherein the interleaving includes the number of paths and delay unit as parameters, the controller changes the number of paths and the delay unit depending on the credibility value, and the code length and the parity length change in synchronization with the number of paths and the delay unit.

10 . An information processing apparatus comprising
a semiconductor memory device, the device comprising: an encoder configured to generate an error correction code with respect to data; a first processor configured to perform interleaving with respect to data from the encoder after the generation of the error correction code; a memory configured to store a process result from the first processor; a detector configured to detect a credibility value indicative of credibility of the data read from the memory; and a controller configured to determine whether or not the credibility value of the data read from a predetermined area of the memory is equal to or greater than a predetermined value based on a detection result from the detector, the controller configured to perform the interleaving with respect to the data read from the predetermined area if the credibility value is equal to or greater than the predetermined value.

11 . A semiconductor memory device comprising:
an encoder configured to generate an error correction code with respect to data; a processor configured to perform interleaving with respect to the data output from the encoder after the generation of the error correction code by the encoder; and a memory configured to store a process result from the processor.

12 . The semiconductor memory device of claim 11 , comprising a detector configured to detect a mean value of an error data per unit time with respect to data read from a predetermined area of the memory, and a controller configured to executes the processor based on the mean value detected by the detector.

13 . The semiconductor memory device of claim 11 , wherein the processor includes the number of paths and delay unit as parameters, and the controller changes the number of paths and delay unit based on the detection result.

Assignees

• Toshiba Kk

Inventors

• Abe Masahiro

Classifications

• G06F11/1068 Primary

  in sector programmable memories, e.g. flash disk (G06F11/1072 takes precedence) · CPC title

• G11C29/52

  Protection of memory contents; Detection of errors in memory contents · CPC title

• H03M13/2792

  Interleaver wherein interleaving is performed jointly with another technique such as puncturing, multiplexing or routing · CPC title

• H03M13/2732 Primary

  Convolutional interleaver; Interleavers using shift-registers or delay lines like, e.g. Ramsey type interleaver · CPC title

• H03M13/353

  Adaptation to the channel · CPC title