scope:

There are many safety issues and requirements involved with the use of logic devices. Some are addressed by MIL-STD-1316, MIL-STD-1911, MIL-STD-1901 and STANAG-4187, STANAG-4497, STANAG-4368 and may be reiterated here. This document is intended to clarify these requirements as applied to Safety Features (SFs) implemented with logic devices. These include but are not limited to: programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), microcontrollers, discrete logic, etc.

While some logic devices may be viewed as better suited for safety applications, it is important to note:

a. All logic devices can be implemented in an unsafe manner.

b. There are potential safety issues associated with the use of any type of logic device in safety critical applications.

c. Individual technologies may require measures not specifically addressed here.

Appendix A provides further clarification of the requirements in Section 2. Appendix B provides definitions.