Physical layout design and analysis of charge recycling SRAM system with write-assist feature in 90nm CMOS technology

摘要

Transistor leakage power will account for more than 50% of total chip power as process technology advances into submicron regime. To counter increasing subthreshold leakage current in traditional SRAM, a new 6T single-ended input/output WA-SRAM is analyzed. WA-SRAM employs a charge-recycling technique to reduce static power of large size SRAM. This thesis describes the physical layout implementation of a 2KByte WA-SRAM system in 90nm CMOS technology and the analysis of the effectiveness of a charge recycling technique. The WA-SRAM exhibits 75% less leakage power per bit than standard SRAM cells in standby mode. Most dynamic operations of WA-SRAM exhibit less active power consumption than standard SRAM with a few exceptions. The exceptions are highly dependent on the type of operation of the previous cycle. The WA-SRAM has shown the potential of supplying the recycled charges to other circuits as a power source when cache size exceeds 9Kbytes.