The Intersil HS-82C54RH is a high performance, radiation hardened CMOS version of the industry standard 8254 and is manufactured using a hardened field, self-aligned silicon gate CMOS process. It has three independently programmable and functional 16-bit counters, each capable of handling clock input frequencies of up to 5MHz. Six programmable timer modes allow the HS-82C54RH to be used as an event counter, elapsed time indicator, a programmable one-shot, or for any other timing application. The high performance, radiation hardness, and industry standard configuration of the HS-82C54RH make it compatible with the HS-80C86RH radiation hardened microprocessor.