Memory and communication architectures have a significant impact on the cost, performance, and time-to-market of complex multiprocessor system-on-chip (MPSoC) designs. The memory architecture dictates most of the data traffic flow in a design, which in turn influences the design of the communication architecture. Thus, there is a need to cosynthesize the memory and communication architectures to avoid making suboptimal design decisions. This is in contrast to traditional platform-based design approaches where memory and communication architectures are synthesized separately. In this paper, the authors propose an automated application-specific cosynthesis framework for memory and communication architecture (COSMECA) in MPSoC designs. The primary objective is to design a communication architecture having the least number of buses, which satisfies performance and memory-area constraints, while the secondary objective is to reduce the memory-area cost. Results of applying COSMECA to several industrial strength MPSoC applications from the networking domain indicate a saving of as much as 40% in number of buses and 29% in memory area compared to the traditional approach.

As system-on-chip (SoC) designs become more complex, it is becoming harder to design communication architectures to handle the ever increasing volumes of inter-component communication. Manual traversal of the vast communication design space to synthesize a communication architecture that meets performance requirements becomes infeasible. In this paper, we address this problem by proposing an automated approach for floorplan-aware bus architecture synthesis (FABSYN) to synthesize cost-effective, bus-based communication architectures that satisfy the performance constraints in a design. Our synthesis approach incorporates a high-level floorplanning and wire delay estimation engine to evaluate the feasibility of the synthesized bus architecture and detect bus cycle time violations early in the design flow, at the system level. We present case studies of network communication SoC subsystems for which we synthesized bus architectures, detected and eliminated timing violations, and generated core placements in a matter of hours instead of several days for a manual effort.

We present a high-level synthesis methodology that applies a coordinated set of coarse-grain and fine-grain parallelizing transformations. The transformations are applied both during a presynthesis phase and during scheduling, with the objective of optimizing the results of synthesis and reducing the impact of control flow constructs on the quality of results. We first apply a set of source level presynthesis transformations that include common sub-expression elimination (CSE), copy propagation, dead code elimination and loop-invariant code motion, along with more coarse-level code restructuring transformations such as loop unrolling. We then explore scheduling techniques that use a set of aggressive speculative code motions to maximally parallelize the design by re-ordering, speculating and sometimes even duplicating operations in the design. In particular, we present a new technique called "Dynamic CSE" that dynamically coordinates CSE and code motions such as speculation and conditional speculation during scheduling. We implemented our parallelizing high-level synthesis in the SPARK framework. This framework takes a behavioral description in ANSI-C as input and generates synthesizable register-transfer level VHDL. Our results from computationally expensive portions of three moderately complex design targets, namely, MPEG-1, MPEG-2 and the GIMP image processing too], validate the utility of our approach to the behavioral synthesis of designs with complex control flows.