A high-speed, radiation-hard code generator LSI array has been developed and fabricated. A unique design approach combined with hard silicon-gate CMOS/ SOS processing has resulted in an ultra-high transientupset threshold (~1011 rads/s for 50 ns pulse width) and megarad total-dose hardness. This paper describes the design as well as characterizes the electrical, radiation and temperature capabilities of this device. Even with modified design and the radiation-hard process, the code generator achieves better than 20 megabit per second operation. The measured 25Â°C and 125Â°C clock-to-output propagation delays are 46 and 52 ns respectively prior to radiation exposure. The measured clock-to-output propagation delay after 106 rads (si) is 55 ns. These results demonstrate Si-gate CMOS/SOS as a successful radiation-hard LSI technology.