An improved dynamic optically reconfigurable gate array

To date, we have proposed Dynamic Optically Reconfigurable Gate Arrays (DORGAs), the implemented photodiodes of which serve not only as receivers but also as memory. DORGA offers the merit of easily providing a high gate count optically reconfigurable gate array (ORGA) because each reconfiguration circuit consists of only a photodiode and a refresh transistor. However, even though the fast reconfiguration capability has been confirmed as less than 6 ns, such systems have a demerit: their gate arrays can not function during reconfiguration. Consequently, re-configuration and operation of the implemented circuit on a gate array can not be executed in parallel. Because of that fact, the dynamical reconfiguration frequency of DORGA is slow compared to those of ORGAs with latches, flip-flops, or memory. For that reason, this paper proposes a new optical reconfiguration architecture. Using it, the reconfiguration and implemented circuit operation on a gate array are executable in parallel merely by adding a pass transistor. The new design of a 476-gate-count improved DORGA using a standard 0.35 μm three-metal CMOS process technology is also shown.