A novel approach is proposed in this paper for the implementation
of 2D DWT using hybrid wave-pipelining (WP). A digital circuit may be operated at a higher
frequency by using either pipelining or WP. Pipelining requires additional registers and it results
in more area, power dissipation and clock routing complexity. Wave-pipelining does not have any
of these disadvantages but requires complex trial and error procedure for tuning the clock period
and clock skew between input and output registers. In this paper, a hybrid scheme is proposed to
get the benefits of both pipelining and WP techniques. In this paper, two automation schemes are
proposed for the implementation of 2D DWT using hybrid WP on both
Xilinx, San Jose, CA, USA and Altera FPGAs. In the first scheme, Built-in self-test (BIST)
approach is used to choose the clock skew and clock period for I/O registers between the wave-pipelined
blocks. In the second approach, an on-chip soft-core processor is used to choose the clock skew and clock
period. The results for the hybrid WP are compared with nonpipelined and pipelined approaches. From the
implementation results, the hybrid WP scheme requires the same area but faster than the nonpipelined
scheme by a factor of 1.25–1.39. The pipelined scheme is faster than the hybrid scheme by a
factor of 1.15–1.39 at the cost of an increase in the number of registers by a factor of 1.78–2.73,
increase in the number of LEs by a factor of 1.11–1.32 and it increases the clock routing complexity.
More practical bounded-skew clock routing