Allocation of FPGA DSP-Macros in Multi-Process High-Level Synthesis Systems

High-Level Synthesis (HLS) is a single process synthesis method that has shown to produce very good results compared to hand coded RTL, especially for DSP-related applications. At the same time FPGAs are reaching capacities that allow entire systems to be implemented on them. Most of these systems are also DSP-related and make intensive use of the FPGAs' embedded hardmacros (e.g. DSP-blocks). This works presents a method to efficiently allocate DSP-macros in multi-process systems created using HLS in order to minimize the overall area. The proposed method calculates the area sensitivity of each process when its multiply-accumulate (MAC) operations are either mapped onto the FPGA's hardmacro or its configurable resources and allocates the available hardmacros across all processes. Experimental results show that our method creates very good results compared to the optimal solution at a negligible running time.