RAM is one of the most important macro-cells of FPGA,and RTL synthesis plays a critical role on the effective use of RAM resources in FPGA development.For the difficulty of multi-resources and multi-targets in RAM technology mapping of RTL synthesis,this paper presents a method of technology mapping for FPGA on-chip RAM.In this method,an unified technology-independent RAM model is proposed,and based on this model,RAM technology mapping is performed through a series of steps,including model set-up,mode-matching,cost calculation,and binding.When applied in RTL synthesis,this method is capable of mapping various styles of RAM RTL descriptions into the most appropriate type and number of FPGA on-chip RAM resources.Experimental result shows that this method achieves comparable RAM mapping results as the mainstream FPGA RTL synthesis tools-Synplify and XST,this technology has been integrated into the self-developed RTL synthesis-Hqsyn and has been applied into the FPGA market.
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