Novel fault-tolerant techniques for high capacity RAMs

In the area of high capacity RAMs, the memory columns (rows), including the redundancies, are partitioned into column blocks (row blocks), respectively. If the replacement is performed at the row-block level, then a row block-based FTM (RBFTM) system is used. Alternatively, if the replacement is performed at the column-block level, then a column block-based FTM (CBFTM) system is used. If both approaches are incorporated into a memory chip, then the hybrid FTM (HFTM) system is achieved. Experimental results and analysis show that our fault-tolerant architectures can improve the yield for memory fabrication significantly. The reconfiguration mechanism requires almost negligible hardware overhead for high capacity memories. Moreover, the repair rates among different fault-tolerant strategies are also compared