Memory elements with soft error upset immunity

Abstract

Integrated circuits with memory cells are provided. A memory cell may have four inverter-like circuits connected in a ring configuration and four corresponding storage nodes. The four inverter-like circuits may form a storage portion of the memory cell. Some of the inverter-like circuits may have tri-state transistors in pull-up and pull-down paths. The tri-state transistors may be controlled by address signals. Address and access transistors may be coupled between some of the storages nodes and a data line. The address and access transistors may be used to read and write into the memory cell. During write operations, the address signals may be asserted to turn off the tri-state transistors and eliminate contention current from the cell. During read and normal operations, the address signals may be deasserted to allow the inverter-like circuits to hold the current state of the cell while providing soft error upset immunity.