Semiconductor memory, operating method of semiconductor memory, and system
AssigneeFujitsu Semiconductor Limited
InventorKuninori Kawabata
Life of this patent
Estimating the term…
Abstract
In a write operation, an error of regular data read from a regular memory cell is detected and corrected using parity data. A part of the corrected regular data is replaced with write data, to thereby generate new parity data. When write commands are supplied, the parity data starts to be read from a parity memory cell after the read of the regular data is started and while the regular data is read. Further, while the new parity data is supplied to the parity memory cell, the regular data starts to be read from the regular memory cell in response to a following write command. Accordingly, an access cycle time of a semiconductor memory can be reduced.
Claims20
A semiconductor memory, comprising:
- a plurality of regular memory cells to hold regular data written therein;
- a regular data control circuit to input or output the regular data to or from the regular memory cells;
- a parity memory cell to hold parity data of the regular data;
- a parity data control circuit to input or output the parity data to or from the parity memory cell;
- an error correction unit, coupled to the regular data control circuit and the parity data control circuit, to detect and correct an error of the regular data read from the regular memory cells using the regular data read from the regular memory cells and the parity data read from the parity memory cell in a write operation, to generate replaced regular data by replacing a part of corrected regular data with write data, to generate a parity write data using the replaced regular data, and to write the parity write data into the parity memory cell;
- and
- an access control circuit to generate regular access control signals to control the regular memory cells and the regular data control circuit to read the regular data from the regular memory cells and write the regular data into the regular memory cells when write commands are supplied, to generate parity access control signals to control the parity memory cell and the parity data control circuit to start a read of the parity data from the parity memory cell after the regular data starts to be read from the regular memory cells and during the read of the regular data, and to generate the regular access control signals to read the regular data from the regular memory cells in response to a following write command during the parity write data to be written into the parity memory cell is supplied to the parity memory cell.
An operating method of a semiconductor memory having a plurality of regular memory cells holding regular data written therein, a regular data control circuit to input or output the regular data to or from the regular memory cells, a parity memory cell holding parity data of the regular data, a parity data control circuit to input or output the parity data to or from the parity memory cell, and an error correction unit correcting an error of the regular data, the operating method comprising:
- detecting and correcting, in a write operation, the error of the regular data read from the regular memory cells using the regular data read from the regular memory cells and the parity data read from the parity memory cell;
- generating replaced regular data by replacing a part of corrected regular data with write data, generating a parity write data using the replaced regular data, and writing the new parity data into the parity memory cell;
- generating regular access controls signal controlling the regular memory cells and the regular data control circuit to read the regular data from the regular memory cells and write the regular data into the regular memory cells when write commands are supplied;
- generating parity access control signals controlling the parity memory cell and the parity data control circuit to start a read of the parity data from the parity memory cell after the regular data starts to be read from the regular memory cells and during the read of the regular data;
- and
- generating the regular access control signals to read the regular data from the regular memory cells in response to a write command while the parity write data to be written into the parity memory cell is supplied to the parity memory cell.
A system comprising a semiconductor memory and a controller to control an access to the semiconductor memory, wherein
- the semiconductor memory comprises:
- a plurality of regular memory cells to hold regular data written therein;
- a regular data control circuit to input or output the regular data to or from the regular memory cells;
- a parity memory cell to hold parity data of the regular data;
- a parity data control circuit to input or output the parity data to or from the parity memory cell;
- an error correction unit being coupled to the regular data control circuit and the parity data control circuit, to detect and correct an error of the regular data read from the regular memory cells using the regular data read from the regular memory cells and the parity data read from the parity memory cell in a write operation, to generate replaced regular data by replacing a part of corrected regular data with write data, to generate a parity write data using the replaced regular data, and to write the parity write data into the parity memory cell;
- and
- an access control circuit to generate regular access control signals to control the regular memory cells and the regular data control circuit to read the regular data from the regular memory cells and write the regular data into the regular memory cells when write commands are supplied, to generate parity access control signals to control the parity memory cell and the parity data control circuit to start a read of the parity data from the parity memory cell after the regular data starts to be read from the regular memory cells and during the read of the regular data, and to generate the regular access control signals to read the regular data from the regular memory cells in response to a following write command during the parity write data to be written into the parity memory cell is supplied to the parity memory cell.
Dependencies are inferred from the claim text.