PAM-Blox II: Design and Evaluation of C++ Module Generation for Computing with FPGAs
[IEEE Conference on Field Programmable Custom Computing Machines, Napa, April 2002]
Oskar Mencer

abstract.

This paper explores the implications of integrating flexible module generation 
into a compiler for FPGAs. The objective is to improve the programmability of 
FPGAs, or in other words, the productivity of the FPGA programmer. 
We describe (1) the module generation library \emph{PAM-Blox II}, 
the second generation of object-oriented module generators in C++, 
targeted at computing with FPGAs, and (2) examples of design tradeoffs and 
performance results using redundant representations for addition and 
multiplication, and technology mapping of comparison and elementary 
function evaluation. 

PAM-Blox II is built on top of a set of extensions to the gate level FPGA 
design library PamDC to provide a more efficient, portable, scalable, and 
maintainable module generator library. Using PAM-Blox II we demonstrate a 
simplified interface to bit-level programability. The simplification results 
from the bottom-up approach and a close coupling of architecture generation, 
module generation and gate level CAD.

The tradeoffs for the module generators are based on trading area for speed 
and hand-optimizing technology mapping to the specific FPGA technology. 
As an example, we show that redundant number representations hold one 
key to unleashing the full potential of reconfigurability on the bit-level. 
The presented module generators are applied to encryption and compression 
to show the impact of the bit-level optimizations on application performance.