 applications; soft error (or soft error rate (SER)) is the term used by most terrestrial applications. Multiple Bit Upset (MBU) is the condition in which two or more errors (SEUs) are produced by the passage of an ionizing particle through the device structure. This may occur due to the particle traversing sensitive volumes within the circuitry of more than one bit cell, or due to conditions on control or clock signals which result in more than a single bit being upset. 4.3.2 Single Event Transients in Analog Circuits As described above in digital devices, Single Event Transient (SET) is a voltage waveform impressed upon a signal within a device due to the collection of charge generated by the passage of an ionizing particle through the device structure. The transient propagates through device circuitry appearing as a pulse on the output of analog microelectronic devices. 4.3.3 Single Event Functional Interrupt [Koga97] [LaBel98] Single Event Functional Interrupt (SEFI) is a component level phenomenon describing the condition in which the function of the device is compromised as the consequence of an SEU occurring within the component. The single event upset typically affects the control logic within the device causing device mode or programming control to be modified, or device test modes to be invoked which alter the overall function of the component. SEFI has been observed in microprocessors, electrically erasable programmable read only memory (EEPROM), dynamic random access memory (DRAM), and digital signal processor (DSP) devices. Systems Engineering for Space Radiation Environment Compatibility Procedures for assuring design compatibility with the space radiation environment consist of understanding the environment, specifically describing the environment at the level of interaction with sensitive devices and technologies, understanding the effects produced by the environment on devices, assessing the consequences of component level effects on system operation, and the development of application level stra