A VLSI implementation of a dedicated digital signal processor is presented.
The processor is tailored for efficient implementation of transform domain
adaptive filters. It incorporates a butterfly processor which performs but
terfly operation to implement the required transformation. It is also able
to perform complex addition, subtraction and multiplication. The butterfly
processor makes use of a redundant binary tree multiplier with a recently p
roposed coding of signed-digit numbers which reduces the number of levels i
n the tree by one. An on-chip read only memory holds the transformation coe
fficients. The contents of the ROM determine the type of transform. The pro
cessor incorporates an ALU to perform integer arithmetic, address calculati
ons and implementation of circular memory scheme. For fastest accessibility
, the essential variables of the algorithm are implemented in a register fi
re.