From: Luke Kenneth Casson Leighton Date: Tue, 26 Oct 2021 12:47:10 +0000 (+0100) Subject: add fft butterfly diagram X-Git-Tag: opf_rfc_ls005_v1~3523 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0b272b4d43e1c24cd50c783064a85154a0c2defd;p=libreriscv.git add fft butterfly diagram --- diff --git a/conferences/openpower2021/fft_butterfly.png b/conferences/openpower2021/fft_butterfly.png new file mode 100644 index 000000000..1bb3c2acd Binary files /dev/null and b/conferences/openpower2021/fft_butterfly.png differ diff --git a/conferences/openpower2021/openpower_2021.tex b/conferences/openpower2021/openpower_2021.tex index 71d844309..ff1e7500a 100644 --- a/conferences/openpower2021/openpower_2021.tex +++ b/conferences/openpower2021/openpower_2021.tex @@ -242,14 +242,15 @@ sv.fmadds: uses fp0 as accumulator \end{itemize} } -\frame{\frametitle{nmigen PowerISA Decoder} + +\frame{\frametitle{Discrete Cosine Transform (DCT): Basics} \begin{itemize} \item Standard DCT Schedule (messy, impossible for SIMD) \item Output is in bit-reversed order\\ 0b000 = 0b000 (in: 0 out: 0)\\ - 0b001 = 0b100 (in: 1 out: 4)\\ - 0b110 = 0b011 (in: 7 out: 3) + 0b001 = 0b100 (in: 1 out: 4) ...\\ + 0b110 = 0b011 (in: 6 out: 3)\\ 0b111 = 0b111 (in: 7 out: 7) \end{itemize} @@ -259,6 +260,19 @@ sv.fmadds: uses fp0 as accumulator } +\frame{\frametitle{Fast Fourier Transform (FFT/DFT): Butterfly Basics} + + \begin{itemize} + \item Standard Butterfly Schedule (again: messy, but less so) + \item Output, again, is in bit-reversed order + \end{itemize} + +\begin{center} +\includegraphics[width=0.70\textwidth]{fft_butterfly.png} +\end{center} + +} + \frame{\frametitle{TODO rewrite Summary}