Repairing Advanced-Memory Buffer (AMB) with redundant memory buffer for repairing DRAM on a fully-buffered memory-module
US7474576B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 2008 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Mar 21, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/88
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A repairing fully-buffered memory module can have memory chips with some defects such as single-bit errors. A repair controller is added to the Advanced Memory Buffer (AMB) on the memory module. The AMB fully buffers memory requests that are sent as serial packets over southbound lanes from a host. Memory-access addresses are extracted from the serial packets by the AMB. The repair controller compares the memory-access addresses to repair addresses and diverts access from defective memory chips to a spare memory for the repair addresses. The repair addresses can be located during testing of the memory module and programmed into a repair address buffer on the AMB. The repair addresses 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 the repair address buffer on the AMB during power-up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.