An embedded DRAM-FPGA chip with instantaneous logic reconfiguration

Reconfigurable computing is attracting wide attention as a novel general purpose computing paradigm for accelerating compute intensive and/or data-parallel applications, such as compression, encryption, searching, sorting, and image processing. A key enabling technology for a reconfigurable computer is in-system logic reconfiguration of SRAM-based FPGAs, through which its hardware architecture is dynamically customized for a specific task on demand. Quicker a reconfiguration is, more frequent the reconfigurations can become: i.e., a reconfigurable computer can adapt to applications which have more dynamic behavior. A whole-chip reconfiguration in conventional FPGAs, however, takes at least 100μs. With this long latency, a reconfigurable computer is adaptable only to static applications, substantially losing the general-purposeness of the original concept. Integrating a DRAM with an FPGA can become an ideal solution to this problem. The on-chip DRAM can store hundreds of configuration programs, and the logic reconfiguration can get extremely faster by context-switching among the programs utilizing huge bandwidth internal to the DRAM core. Being driven by this observation, we have conducted prototype design of an embedded DRAM-FPGA chip