Book excerpt: The Arm(R) Cortex(R)-M processors are already one of the most popular choices for loT and embedded applications. With Arm Flexible Access and DesignStart(TM), accessing Arm Cortex-M processor IP is fast, affordable, and easy. This book introduces all the key topics that system-on-chip (SoC) and FPGA designers need to know when integrating a Cortex-M processor into their design, including bus protocols, bus interconnect, and peripheral designs. Joseph Yiu is a distinguished Arm engineer who began designing SoCs back in 2000 and has been a leader in this field for nearly twenty years. Joseph's book takes an expert look at what SoC designers need to know when incorporating Cortex-M processors into their systems. He discusses the on-chip bus protocol specifications (AMBA, AHB, and APB), used by Arm processors and a wide range of on-chip digital components such as memory interfaces, peripherals, and debug components. Software development and advanced design considerations are also covered. The journey concludes with 'Putting the system together', a designer's eye view of a simple microcontroller-like design based on the Cortex-M3 processor (DesignStart) that uses the components that you will have learned to create.