memory cell system is disclosed with properties of asymmetrical operation such that the occurrence of memory error due to certain environmental disturbances is detectable the asymmetry of operation can be adjusted to set the level at which the disturbance is detected detection of memory error in the system can be used to shut off access to an associated memory array in order to prevent error in the array application_number US 90174392 A description the invention is used in connection with an associated memory array in order to detect the occurrence of a condition that is likely to cause error in the array or the high likelihood of impending error in the array the invention uses a detection memory cell as a transient dose detector by introducing some asymmetry so that the cell has a favored state on set or re set a write into the cell places the detection memory cell in an unfavored state under sufficient radiation effects or power down situations the detection memory cell switches to the favored state the asymmetry introduced to the cell must be such that the cell will change to the favored state at a transient dose level or accumulated radiation level that is approaching the level at which cells in the associated memory array may be upset or at which associated circuitry will fail one way to do this is to introduce an asymmetry on the bit lines of the.