Immunity evaluation of SRAM core using DPI with on-chip diagnosis structures

A direct power injection (DPI) method evaluates the immunity of a static random access memory (SRAM) core in a 90 nm CMOS technology, with on-die diagnosis structures of memory built-in self test (MBIST) and on-chip voltage waveform monitoring (OCM). The magnitude of sinusoidal voltage variation introduced by DPI is quantified by OCM. The number of resultant erroneous bits as well as their distribution in the cell array is given by MBIST. The DPI, OCM, and MBIST co-operate for the immunity diagnosis of an SRAM core, as a function of power and frequency of injection. The frequency-dependent sensitivity reflects the highly capacitive nature of densely integrated memory cells.