CMOS Process Photodiode Memory

Demand for high-speed dynamic reconfiguration of a programmable device is increasing for raising the performance level of such devices. To support high-speed dynamic reconfiguration, optically reconfigurable gate arrays (ORGAs) have been developed. An ORGA consists of a holographic memory, a laser array, and an optically reconfigurable gate array VLSI. The holographic memory can store many configuration contexts. Moreover, its large-bandwidth optical connection enables high-speed reconfiguration.Nevertheless,in previously proposed ORGA-VLSIs,the static configuration memory to store a single configuration context consumed a large implementation area of the ORGA-VLSIs and prevented the realization of large-gate-count ORGA-VLSIs. Therefore, a CMOS process photodiode memory has been newly fabricated to increase the gate density of ORGAs. The photodiode memory uses the junction capacitance of photodiodes as dynamic memory, thereby obviating the static configuration memory.