This book is a generic user guide for devices that implement the ARM Cortex-M0+ processor. Implementers of Cortex-M0+ processor designs make a number of implementation choices, that can affect the functionality of the device. This means that, in this book:
some information is described as implementation-defined
some features are described as optional.
See the documentation from the supplier of your Cortex-M0+ device for more information about these features.
In this book, unless the context indicates otherwise:
Refers to the Cortex-M0+ processor, as supplied by ARM.
Refers to an implemented device, supplied by an ARM partner, that incorporates a Cortex-M0+ processor. In particular, your device refers to the particular implementation of the Cortex-M0+ processor that you are using. Some features of your device depend on the implementation choices made by the ARM partner that made the device.