From e1f62a6c7e444892872b79f264d322b517e84462 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Thu, 21 Jun 2018 12:13:16 +0100 Subject: [PATCH] update --- pinmux/pinmux_chennai_2018.tex | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/pinmux/pinmux_chennai_2018.tex b/pinmux/pinmux_chennai_2018.tex index d8fd4b437..b80c81cdf 100644 --- a/pinmux/pinmux_chennai_2018.tex +++ b/pinmux/pinmux_chennai_2018.tex @@ -260,7 +260,7 @@ In/out: {\bf Note: these all require multiplexing } \begin{itemize} - \item Output-Enable (aka Input disable): switches pad to In or Out + \item Output-Enable (aka Input disable): switches pad to Out or In \item Output (actually an input wire controlling pin's level, HI/LO) \item Input (actually an output wire set based on pin's driven level) \end{itemize} @@ -288,7 +288,7 @@ \begin{itemize} \item Standard Mux design {\bf cannot deal with many-to-one inputs}\\ - (SiFive IOF source code from Freedom U310 cannot, either) + (SiFive IOF source code from Freedom E310 cannot, either) \vspace{4pt} \item I/O pad configuration conflated with In-Muxer conflated with Out-Muxer conflated with GPIO conflated with EINT. @@ -318,9 +318,15 @@ \frame{\frametitle{GPIO (only): Simplified I/O pad Diagram (FN only)} \begin{center} - \includegraphics[height=2.5in]{reg_gpio_pinblock.jpg}\\ - {\bf 3 wires: IN, OUT, OUTEN (also = !INEN) } + \includegraphics[height=1.3in]{reg_gpio_pinblock.jpg} \end{center} + \begin{itemize} + \item GPIO In/Out/Direction is just another FN (effectively) + \item 3 wires: IN, OUT, OUTEN (=INEN\#) + \item FN however may be output-only (UART\_TX), input-only (UART\_RX) + or bi-directional (I2C\_SDA) and Bus-controlled. + \item GPIO is definitely bi-directional and under Register control + \end{itemize} } -- 2.30.2