Memory Hierarchy for MCSoPC Multithreaded Systems.
Erik K. Anderson, Wesley Peck, Jim Stevens, Jason Agron, Fabrice Baijot, Seth Warn, David Andrews · ERSA · 2007
ABSTRACTThanks to advancements in fabrication techniques, it willsoon be possible to place 10’s if not 100’s of cores on asingle hybrid CPU/FPGA reconfigurable chip. This haslead to a new field of study, namely Multi-Core Systemson a Programmable Chip (MCSoPC). The problems beingstudied with MCSoPC are not unlike the problems stud-ied 20 years ago when multiple CPU parallel processingnetworks were first organized to solve computationally in-tensive tasks. With reconfigurable computing the prob-lems are more complex as hardware/software co-design en-gineers would like to create hybrid hard, soft, and customcore solutions, all specified from within a software cen-tric programming model. This paper introduces a new dis-tributed shared memory model that enables the existing Hy-bridthread’s Hardware Thread Interface (HWTI) to providea function call stack and heap for hardware threads. Fea-tures that in turn provide a generalized model for invokingfunctions, support for recursion, and dynamic memory allo-cation. These services were added to the HWTI not onlyto give hardware threads better performance, but providea meaningful and semantic rich target for a HLL to HDLtranslator.1. INTRODUCTIONThe potential benefits of Multi-Core System on a Pro-grammable Chip (MCSoPC) are clear: increased perfor-mance, customizations, and parallelization of tasks. How-ever,thesebenefitsdonotcomewithoutchallenges. InshortMCSoPC are difficult to program. Reasons include unre-alized performance gains, immature programming models[10], undefined targets for hardware tasks, and indetermi-natecommunicationmodelsbetweenhardwareandsoftwaretasks. Ideally programmers would like to specify their MC-SoPC in a known high level language and programmingmodel, and have their design automatically and correctlytranslated to hybrid software and hardware tasks. A numberof research groups have made impressive strides in achiev-ingthisgoal[5,6,16,11,8,14],howevernonethusfarhavebeen able to achieve unaltered high level language to hard-