Title
Enhancing FPGA Device Capabilities by the Automatic Logic Mapping to Additive Carry Chains
Abstract
This paper presents an approach to the automatic mapping of arbitrary combinational circuits to the arithmetic carry-chain structures widely available in modern FPGAs. This capability is highly valuable as it enables the utilization of these fast special-purpose structures for general-purpose logic. The described approach is both automatic and generally applicable to all carry-chain architectures designed for binary addition. It, thus, lifts severe constraints left by previous works. It helps to reduce the pressure on the general-purpose routing resources and accelerates critical logic paths. The proposed mapping is further shown to enhance the logic capability of a logic block containing a k-input lookup table (k-LUT) to implement many (k+1)-input functions on common FPGA architectures. This, in particular, also applies to all logic functions with a non-inverting path as introduced by Anderson and Wang. This makes their envisioned gains in logic density achievable even on current devices without requiring their architectural extension. The benefits of the carry-chain mapping are experimentally evaluated on the basis of combinational MCNC benchmarks. It is shown how carry chains can be recovered within a functional standard mapping and that a device mapping aware of carry chains achieves a reduction of the combinational delay of about a 20 percent.
Year
DOI
Venue
2010
10.1109/FPL.2010.70
FPL
Keywords
Field
DocType
adders,carry logic,field programmable gate arrays,table lookup,FPGA device,arithmetic carry chain structure,automatic logic mapping,binary addition,combinational MCNC benchmark,combinational delay,general purpose logic,logic density,logic path,lookup table,special purpose structure,Carry Chains,FPGA,Logic Synthesis
Logic synthesis,Logic gate,Sequential logic,Logic optimization,Computer science,Programmable logic array,Parallel computing,Algorithm,Combinational logic,Logic block,Logic family,Computer engineering
Conference
Citations 
PageRank 
References 
2
0.41
7
Authors
2
Name
Order
Citations
PageRank
Thomas B. Preusser1586.60
Rainer G. Spallek213725.30