Programmable active memories: reconfigurable systems come of age

摘要

Programmable active memories (PAM) are a novel form of universalnreconfigurable hardware coprocessor. Based on field-programmable gatenarray (FPGA) technology, a PAM is a virtual machine, controlled by anstandard microprocessor, which can be dynamically and indefinitelynreconfigured into a large number of application-specific circuits. PAM'snoffer a new mixture of hardware performance and software versatility. Wenreview the important architectural features of PAM's, through thenexample of DECPeRLe-1, an experimental device built in 1992. PAMnprogramming is presented, in contrast to classical gate-array and fullncustom circuit design. Our emphasis is on large, code-generatednsynchronous systems descriptions; no compromise is made with regard tonthe performance of the target circuits. We exhibit a dozen applicationsnwhere PAM technology proves superior, both in performance and cost, tonevery other existing technology, including supercomputers, massivelynparallel machines, and conventional custom hardware. The fields coveredninclude computer arithmetic, cryptography, error correction, imagenanalysis, stereo vision, video compression, sound synthesis, neuralnnetworks, high-energy physics, thermodynamics, biology and astronomy. Atncomparable cost, the computing power virtually available in a PAMnexceeds that of conventional processors by a factor 10 to 1000,ndepending on the specific application, in 1992. A technology shrinknincreases the performance gap between conventional processors and PAM's.nBy Noyce's law, we predict by how much the performance gap will widennwith time