Fully-buffered memory-module with error-correction code (ecc) controller in serializing advanced-memory buffer (amb) that is transparent to motherboard memory controller

Abstract

An error-correcting fully-buffered memory module can detect and correct some errors in data read from memory chips. An error correction code ECC controller is added to the Advanced Memory Buffer (AMB) on the memory module that fully buffers memory requests sent as serial packets. The error correction controller generates ECC bits for write data, and both the ECC bits and the write data are written to the memory chips by a DRAM controller in the AMB. During reads, an ECC checker generates a syndrome and can activate an error corrector to correct data or signal a non-correctable error. The corrected data is formed into serial packets sent back to the motherboard by the AMB. Configuration data for the ECC controller could be first programmed into a serial-presence-detect electrically-erasable programmable read-only memory (SPD-EEPROM) on the memory module, and then copied to error-correction configuration registers on the AMB during power-up.