DDR5 Memory Layout Using Locked RAID for Chipkill Protection

The patent extracts the SEC functionality from the memory die and relocates it to the memory controller. The memory controller implements SEC logic that operates on data received from multiple dice, thereby providing error correction without requiring additional SEC bits on each memory die. This resolves the contradiction by maintaining error correction capability while eliminating the die area overhead of on-die SEC bits.

The patent introduces an intermediary layer (the memory controller) that performs SEC operations on data from multiple dice. Instead of each die having its own SEC bits, the memory controller acts as an intermediary that collects data from multiple dice and applies SEC across the combined data set. This intermediary approach provides error correction capability without increasing individual die area.

The patent replaces complex Reed-Solomon coding with simpler, more efficient error correction mechanisms. Specifically, it uses SEC-DAC (Single Error Correction, Double Error Detection) coding and RAID-like parity schemes that are computationally less intensive than full Reed-Solomon decoding. These simpler codes provide adequate chipkill protection without the high computational overhead of Reed-Solomon, thereby reducing device complexity while maintaining reliability.

The patent changes the error correction parameters from strong Reed-Solomon codes to lighter SEC-DAC and parity-based schemes. By adjusting the error correction capability parameters to match the actual error rates and requirements, the system achieves adequate chipkill protection with reduced computational complexity. The patent optimizes the balance between protection level and processing overhead by selecting appropriate code parameters.

The patent extracts the Reed-Solomon parity storage requirement and replaces it with more space-efficient error correction mechanisms. By moving SEC to the controller and using lighter parity schemes, the system reduces the number of dedicated parity dice needed. This allows better utilization of storage space while maintaining chipkill protection capability.

The patent merges the functions of data storage and error correction more efficiently. Instead of separating data dice and parity dice as in traditional Reed-Solomon implementations, the system uses RAID-like configurations where parity information is distributed and integrated with data storage. This merging approach improves storage space efficiency by reducing the overhead dedicated to error correction while maintaining protection against chipkill failures.