Static and Dynamic Reconfigurable Designs for a 2D Shape-Adaptive DCT

摘要

This paper presents two reconfigurable design approaches for a two dimensional Shape-Adaptive Discrete Cosine Transform (2D SA-DCT). The SA-DCT is an example of a new type of multimedia video processing algorithm where the computations performed are data dependent. A static design, where the configuration does not change during execution of the task, is presented. The use of a data dependence graph (DDG) is proposed which represents the computations and input signals required to calculate a particular output signal depending on a variable input parameter. By re-structuring the DDG and exploiting possible sharing of FPGA resources for different entities within the SA-DCT, it is demonstrated that the area required for an implementation can be significantly reduced. An alternative dynamic approach is also introduced where the FPGA's configuration may change over time. This is well suited to using dynamically reconfigurable logic but suffers from long reconfiguration time if current FPGAs are used.