This library provides low level hardware abstraction for an AT91SAM7S
ARM microcontroller (with an ARM7TDMI ARM Thumb Processor).

These routines are design primarily for a bare-metal system.  The
philosophy is not to block (well at not least for long).


TODO
Convert files to use doxygen markup

Perhaps use CMSIS - Cortex Microcontroller Software Interface Standard


A note on handles.  These are designed to be opaque pointers or
integers and to provide a consistent interface.  This improves
portability but can be unnecessarily confusing.  Moreover, opaque
pointers hinder debugging.  In hindsight, I'd remove the opacity.

From a consistent interface point of view, the only exception is
pio_t.  Dereferencing a pointer stymies many optimisations, especially
for low performance microcontrollers.

adc_t
pwm_t
spi_t
ssc_t
tc_t
udp_t
usart_t

pio_t  (uint32)