Clarify the usage, range and mapping for the set of window indexes of each cyclic shift for the FFT processing pipeline.
Signed-off-by: Nicolas Chautru <nicolas.chau...@intel.com> --- doc/guides/prog_guide/bbdev.rst | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/doc/guides/prog_guide/bbdev.rst b/doc/guides/prog_guide/bbdev.rst index 6f1f3f65fb..064c2b1fe6 100644 --- a/doc/guides/prog_guide/bbdev.rst +++ b/doc/guides/prog_guide/bbdev.rst @@ -296,8 +296,11 @@ Capabilities details for FFT function The total number of distinct time windows supported for the post-FFT point-wise multiplication is exposed as ``fft_windows_num``. -The ``window_index`` provided for each cyclic shift -in each ``rte_bbdev_op_fft`` operation is expected to be limited to that size. +The ``window_index`` provided for each cyclic shift in each ``rte_bbdev_op_fft`` operation is +expected to be within the range (0 to ``fft_windows_num`` - 1). +These indexes for up to 12 cyclic shifts are mapped consecutively into an array of 6 bytes +(ie. the first index is the first 4 most significant bits of the first byte, etc...): +``uint8_t window_index[RTE_BBDEV_MAX_CS_2]``. The information related to the width of each of these pre-configured window is also exposed using the ``fft_window_width`` array. -- 2.34.1
