High-speed programmable logic arrays in ESFI SOS technology

Exploratory MOS programmable logic array (PLA's) operating up to a clock frequency of 22 MHz have been realized and successfully operated. These PLA's used dynamic logic gates and are built in epitaxial-silicon films on insulators (ESFI) silicon-on-sapphire (SOS) technology. The problems arising with the use of these dynamic gates in a two-stage logic array are discussed and different circuits are presented. The advantage of these circuits, in addition to their high speeds, is reduced power consumption, and the possibility to determine the number of feedback loops when the array is personalized. The features of the circuits are compared with each other with a complete PLA described in an earlier paper (see ibid., vol. SC-10, p.331 (1975)). The results gained from computer simulations agree reasonably well with the experimental results.