This isn’t a book for the faint of heart. The Arduino Due is quite a different beast compared to the more common Arduino Uno. It uses the Arm Cortex-M3 microcontroller SAM3×8E from Microchip (formerly Atmel). Learning the internals of the Due is a possible bridge from the more straightforward world of the Arduino into the much more complicated world of Arm. If you’ve come this far, I assume that you have ambitions way beyond using only the Arduino API. This is a journey into the world of Arm. Coverage includes the internals of:

Uploading over the programming port and the native port
The boot sequence from power-on to setup() and loop()
The clock tree
Digital I/O, including glitch filtering and debouncing
Interrupts, including SysTick and the NVIC
Flashing and debugging via JTAG
Bare metal development for the Due with the GNU Arm Embedded Toolchain and makefiles
Time and delays
The Serial object
analogWrite()
analogRead()
The USB stack including the UDD, the USB Core, PluggableUSB, PluggableUSBModule, the HID Library, the Mouse Library, and the Keyboard Library
The SPI Library
The Wire Library (I2C)