High reliability CMOS SRAM with built-in soft defect detection

This paper will describe a newly developed circuit technique that detects all possible process defects which may cause data retention or non-static failures in a CMOS SRAM array. The technique, dubbed Soft defect detection (SDD), can accomplish the 100% static test, that was unachievable previously, in milliseconds to assure perfect data retention without relying on high temperature hake. The SDD technique has been successfully implemented into the 16K bit SRAM module of a new 32 bit microcontroller.