Abstract
Embedded SRAM macros are widely used to System-On-Chip (SOC) memory because of their higher random access and lower cost per bit. However, increasingly large power consumption is a big problem in SOC system. For this reason, low power design issue should be taken into consideration. For embedded-DRAM, the stored data should be refreshed periodically in self-refresh mode. But at room temperature, the cell data retention time will extend much longer than that in higher temperature condition. Thus, there is an additional AC component of data refresh power at room temperature with conventional period. In the previous work, the scheme of temperature-aware self-refresh (TASFR) control scheme is presented to extend self-refresh period in lower temperature condition. There bubble code effect in the TASFR control scheme, so we proposed a bubble code detector to prevent it in order to completely extend refresh period at room temperature. We apply our design in 65nm eDRAM low leakage process within an 8Mb embedded DRAM macro. The experiment results show that, 98.62% reduction of AC component of data retention power can achieve at room temperature.