Normalized Reciprocal HDL Optimized
Libraries:
Fixed-Point Designer HDL Support /
Math Operations
Description
The Normalized Reciprocal HDL Optimized block computes the normalized reciprocal of u, returned as y and t such that 0.5 < |y| ≤ 1 and 2ey = 1/u.
If u = 0 and u is a fixed-point or scaled-double data type, then y = 2 – eps(y) and e = 2nextpow2(w) – w + f, where
w
is the word length of u and f is the fraction length of u.If u = 0 and u is a floating-point data type, then y =
Inf
and t = 1.
Ports
Input
Output
Algorithms
The Normalized Reciprocal HDL Optimized block works by normalizing the input using a binary search, which has a latency of approximately log2 of the word length of the input, followed by a CORDIC reciprocal kernel, which has a latency approximately the same as the word length of the input.
The Normalized Reciprocal HDL Optimized block is always ready to accept data. After the initial latency, valid samples are output every sample. The latency in samples for a fixed-point input u is
D = ceil(log2(u.WordLength)) + u.WordLength + 5
Extended Capabilities
Version History
Introduced in R2020a