A multi-context holographic memory recording system for Optically Reconfigurable Gate Arrays

Abstract

Optically Reconfigurable Gate Arrays (ORGAs) offer the possibility of providing a virtual gate count that is much larger than those of currently available VLSIs by exploiting the large storage capacity of a holographic memory. The first ORGA was developed to achieve rapid reconfiguration and a number of reconfiguration contexts; it consisted of a gate array VLSI, a holographic memory, and a laser diode array. The ORGA achieved a 16 µs to 20 µs reconfiguration period that was faster than that of FPGAs, with 100 reconfiguration contexts. However, the ORGA requires the gate array to halt during reconfiguration. Therefore, the ORGA can not be reconfigured frequently because of the associated reconfiguration overhead.On the other hand, new ORGA-VLSIs that have less than 10 ns reconfiguration capability without any related overhead have already been fabricated. However, to date, a multi-holographic reconfiguration system that is suitable for such rapidly reconfigurable ORGA-VLSIs without any overhead has never been developed. For such realization, this paper proposes a four-context ORGA architecture and a multi-context holographic memory recording system used for it. In addition, experimentally demonstrated results of recording a holographic memory and reconfiguring an ORGA-VLSI are described.

A Dynamic Optically Reconfigurable Gate Array with a Silver-Halide Holographic Memory

“…The recording particle size is less than 40 nm. This was recorded using a previously developed context writer [13]. An ORGA-VLSI chip that was fabricated using the 0.35 µm triple-metal CMOS process was used.…”

A lens-less imaging holographic memory writer system for a programmable optically reconfigurable gate array

“…Because of those and related difficulties, mixed optical and electrical VLSIs, optically reconfigurable gate arrays (ORGAs) [10]- [15] were developed to achieve both fast reconfiguration and numerous reconfiguration contexts. The ORGA consists of a gate array VLSI, a holographic memory, and a laser diode array.…”

“…To reprogram an ORGA, a holographic memory must be disassembled from its ORGA package and reprogrammed using a holographic memory writer. It must be then implemented onto the ORGA package with high precision beyond the capabilities of manual assembly [14], [15].…”

Scaling prospect of optically differential reconfigurable gate array VLSIs

“…As another high-resolution holographic memory, a silver-halide holographic memory was applied to ORGAs and a multi-context reconfiguration experiment was reported [17]. A hologram writer system for the silverhalide holographic memory of ORGAs has been reported in detail [18]. The following is a brief explanation of a holographic memory pattern generation system.…”

“…After the writing process is completed, the silver-halide holographic memory is implemented onto an ODRGA. Such a mechanism and procedure are described in detail in a previous study [18].…”