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.