\item Pin: an I/O pad. May be driven (input) or may drive (output).
\item FN: term for a single-wire "function", such as UART\_TX,
I2C\_SDA, SDMMC\_D0 etc. may be an input, output or both
- (bi-directional: separate wires are always allocated).
+ (bi-directional case: two wires are always allocated, one
+ for input to the function and one for output from the function).
\item TODO\vspace{10pt}
\end{itemize}
}