Madrone Solutions, Inc.

Other

Motorola Corporation

William Daune Atwell

Michael L Longwell

Jeffrey Van Myers

Thomas K Johnston

David Russell Tipple

Grady L Giles

A Random Access Error Detection and Correction unit (RAEDAC) that incorporates a bit-wise error detection and correction unit (BEDAC) in a memory system. In one embodiment, a word-wise error detection and correction unit (WEDAC) operates in coordination with a BEDAC that performs a bit-wise parity calculation. In another embodiment, a WEDAC operates in coordination with a full bit-wise BEDAC that calculates bit-wise check bits. The RAEDAC may be applied to create a multi-dimensional EDAC where, for example, the memory is partitioned into a stack of planes, and a stack-wise error detection and correction unit (SEDAC) is implemented.

Method and apparatus for error detection and correction

An apparatus for operating a dynamic memory ( ) in a sleep mode. The apparatus writes a predetermined background value to at least a background portion of the memory, and then ceases to refresh the background portion. The background value corresponds to the conductivity type of the memory cell, where N-channel devices have a low value and P-channel devices have a high value. After return from sleep mode, the voltage reference is not impacted by the residual charge in the memory cells. According to one embodiment, a refresh controller ( ) accesses a look up table ( ) to store data indicating the status of memory cells. Prescaling may then adjust the period and duty cycle of the refresh cycle in response to the inactive wordlines via a unit, such as prescaler ( ). In one embodiment, the background value is written to the inactive memory cell ( ) via sense amplifier killer circuitry ( ).

Apparatus for operating an integrated circuit having a sleep mode

A method for tracking errors in a memory system by detecting an error in a bit of a word accessed in the memory and maintaining an error history comprising a record of each of the detected errors. The error history information may be used to configure the memory, such as to add redundancy; or may be used to adjust operating parameters of the memory, such as the periodicity of refresh and/or scrub operations; or may be used to trigger a sensing operation of other parameters in an application system. In one embodiment, a counter increments each time an error is detected and decrements when no error is detected, thereby tracking error patterns.

Method for apparatus for tracking errors in a memory system

A plurality of memory tiles ( ) are arranged to form a tiled memory array ( ) in an integrated circuit device ( ). In accordance with the present invention, each of the memory tiles ( ) in the tiled memory array ( ) has charge source circuitry ( ) to provide the sufficient reference voltages for proper operation of the memory tile ( ). In addition, each memory tile ( ) may include local error detection and correction circuitry ( ). To facilitate reliable operation, each memory tile may also include redundant rows and/or columns, and appropriate redundancy control circuitry ( &Prime;).

Memory tile for use in a tiled memory

A plurality of memory tiles ( ) are arranged to form a tiled memory array ( ) in an integrated circuit device ( ). In accordance with the present invention, each of the memory tiles ( ) in the tiled memory array ( ) has charge source circuitry ( ) to provided the sufficient reference voltages for proper operation of the memory tile ( ). In addition, each memory tile ( ) may include local error detection and correction circuitry ( b). To facilitate reliable operation, each memory tile may also include redundant rows and/or columns, and appropriate redundancy control circuitry ( 41 ).

Tiled memory and memory tile for use therein

A method for operating a dynamic memory ( ) in a sleep mode. The method writes a predetermined background value to at least a background portion of the memory, and then ceases to refresh the background portion. The background value corresponds to the conductivity type of the memory cell, where N-channel devices have a low value and P-channel devices have a high value. After return from sleep mode, the voltage reference is not impacted by the residual charge in the memory cells. According to one embodiment, a refresh controller ( ) accesses a look up table ( ) to store data indicating the status of memory cells. Prescaling may then adjust the period and duty cycle of the refresh cycle in response to the inactive wordlines via a unit, such as prescaler ( ). In one embodiment, the background value is written to the inactive memory cell ( ) via sense amplifier killer circuitry ( ).

Method for operating an integrated circuit having a sleep mode

In one embodiment, a plurality of atomic charge pumps (,) are connected together in series to form a distributed charge source (,). The atomic charge pumps (,) are operated sequentially over time to reduce supply signal noise. In addition, the distibuted charge source (,) is compatible with low power applications because each atomic charge pump (,) can be independently powered down if it is not required.

Distributed charge source

A BIST controller (,) and methodology uses the DRAM controller (,) refresh signals to test the data retention characteristics of a DRAM memory array (,). The BIST controller blocks a fraction of the refresh cycles generated by the DRAM controller to provide a margin of confidence above the DRAM's specified retention time. The BIST controller is especially suited to embedded applications in which access to the memory is indirect and to applications in which the memory system is modular. The invention may also be used to characterize the actual retention time of a particular DRAM allowing the system to optimize the DRAM's refresh interval.

Method and apparatus for verifying and characterizing data retention time in a DRAM using built-in test circuitry

A plurality of memory tiles (,) are arranged to form a tiled memory array (,) in an integrated circuit device (,). In accordance with the present invention, each of the memory tiles (,) in the tiled memory array (,) has charge source circuitry (,) to provide the sufficient reference voltages for proper operation of the memory tile (,). In addition, each memory tile (,) may include local error detection and correction circuitry (,). To facilitate reliable operation, each memory tile may also include redundant rows and/or columns, and appropriate redundancy control circuitry (,&Prime;).

Method for designing a tiled memory

A plurality of memory tiles (22) are arranged to form a tiled memory array (12) in an integrated circuit device (400). In accordance with the present invention, each of the memory tiles (22) in the tiled memory array (12) has charge source circuitry (24) to provide the sufficient reference voltages for proper operation of the memory tile (22). In addition, each memory tile (22) may include local error detection and correction circuitry (36b). To facilitate reliable operation, each memory tile may also include redundant rows and/or columns, and appropriate redundancy control circuitry (32c', 32c').

Method for designing a memory tile for use in a tiled memory

A method and system for performing memory repair via redundant rows of memory uses memory elements (208 and 210) for redundant row selection instead of conventional fuses. An on-chip test controller (110) is capable of testing memory rows (106) either at wafer probe, at final testing after manufacturing, or after memory chip packaging and/or final sale to end users. If this testing identifies faulty memory rows in the memory array at any time, the electrically programmable memory elements (208 and 210) can be internally re-programmed to create a new memory configuration which includes redundant memory rows (108). This new memory configuration is enabled in order to remove the newly-detected and previously-detected faulty memory rows from active memory in the memory array.

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Spicewood, TX, United States of America

William Daune Atwell