2024/01/19 by Mike Hamburg, Hamburg, Mike, Eric Linstadt +5
Computer Science · Engineering · #Advanced Data Storage Technologies #Cryptography and Data Security #FOS: Computer and information sciences #Hardware Architecture (cs.AR) #Information Theory (cs.IT) #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.2401.10688
openalex publication_date 2024/01/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Generalized Reed-Solomon (RS) codes are a common choice for efficient, reliable error correction in memory and communications systems. These codes add 2t extra parity symbols to a block of memory, and can efficiently and reliably correct up to t symbol errors in that block. Decoding is possible beyond this bound, but it is imperfectly reliable and often computationally expensive. Beyond-bound decoding is an important problem to solve for error-correcting Dynamic Random Access Memory (DRAM). These memories are often designed so that each access touches two extra memory devices, so that a failure in any one device can be corrected. But system architectures increasingly require DRAM to store metadata in addition to user data. When the metadata replaces parity data, a single-device failure is then beyond-bound. An error-correction system can either protect each access with a single RS code, or divide it into several segments protected with a shorter code, usually in an Interleaved Reed-Solomon (IRS) configuration. The full-block RS approach is more reliable, both at correcting errors and at preventing silent data corruption (SDC). The IRS option is faster, and is especially efficient at beyond-bound correction of single- or double-device failures. Here we describe a new family of "unraveling" Reed-Solomon codes that bridges the gap between these options. Our codes are full-block generalized RS codes, but they can also be decoded using an IRS decoder. As a result, they combine the speed and beyond-bound correction capabilities of interleaved codes with the robustness of full-block codes, including the ability of the latter to reliably correct failures across multiple devices. We show that unraveling codes are an especially good fit for high-reliability DRAM error correction.