ArchHDL: A Novel Hardware RTL Modeling and High-Speed Simulation Environment

LSIs are generally designed through four stages including architectural design, logic design, circuit design, and physical design. In architectural design and logic design, designers describe their target hardware in RTL. However, they generally use different languages for each phase. Typically a general purpose programming language such as C or C++ and a hardware description language such as Verilog HDL or VHDL are used for architectural design and logic design, respectively. That is time-consuming way for designing a hardware and more efficient design environment is required. In this paper, we propose a new hardware modeling and high-speed simulation environment for architectural design and logic design. Our environment realizes writing and verifying hardware by one language. The environment consists of (1) a new hardware description language called ArchHDL, which enables to simulate hardware faster than Verilog HDL simulation, and (2) a source code translation tool from ArchHDL code to Verilog HDL code. ArchHDL is a new language for hardware RTL modeling based on C++. The key features of this language are that (1) designers describe a combinational circuit as a function and (2) the ArchHDL library realizes non-blocking assignment in C++. Using these features, designers are able to write a hardware transparently from abstracted level description to RTL description in Verilog HDL-like style. Source codes in ArchHDL is converted to Verilog HDL codes by the translation tool and they are used to synthesize for FPGAs or ASICs. As the evaluation of our environment, we implemented a practical many-core processor in ArchHDL and measured the simulation speed on an Intel CPU and an Intel Xeon Phi processor. The simulation speed for the Intel CPU by ArchHDL achieves about 4.5 times faster than the simulation speed by Synopsys VCS. We also confirmed that the RTL simulation by ArchHDL is efficiently parallelized on the Intel Xeon Phi processor. We convert the ArchHDL code to a Verilog HDL code and estimated the hardware utilization on an FPGA. To implement a 48-node many-core processor, 71% of entire resources of a Virtex-7 FPGA are consumed.