A Technique to Measure Short-Term Annealing in MOS Microprocessors

A technique has been developed for the evaluation of the operation of microprocessors (MPU's) at early times and as a function of time after exposure to a radiation pulse. This technique, which was applied to some representative units--The Motorola MC6800L, the Intel C8080A and the Intel D8080A--uses a comparison method to determine functionality of the MPU under test. Following irradiation, a test program is repetitively restarted and run in parallel on the MPU under test and a reference MPU while their address and data outputs are compared. This evaluation technique is adaptable to other MPU's and also to other devices used in a microcomputer system. With 1-μs LINAC irradiation, the failure level of the MC6800L and the D8080A was about 8 krads(Si) and that of the C8080A was about 16 krads(Si). Reverse annealing (progressive degradation) was observed on several samples. Normal annealing was observed for the MC6800L and C8080A samples at hundreds of seconds.