Chapter 8 The Raspberry Pi and the ARM processor The Raspberry Pi is a low-cost experimental platform based on a widely available ARM processor. This chapter describes the main features of the ARM processor and the surrounding hardware of the Raspberry Pi that foster the use of this processor. 8.1 Raspberry Pi overview The advantages of using standardised processors sparked off an interesting devel- opment where companies design processors but leave it to others to manufacture them. An example of this is ARM (Advanced RISC Machine) Holdings. Based in the UK, this company licenses their processor designs to other companies. ARM’s RISC processor designs are market dominant in mobile phones and tablets as they offer greater performance per watt than the Intel x86 processors that use a CISC architecture. However, the debate on whether energy consumption is related to the instruction set has not been settled [7]. Broadcom Incorporated, a company with a background in semiconductors for communication devices, utilise ARM processors in their SoC (System On a Chip) solutions. An SoC incorporates a processor and various supporting circuits onto a single silicon substrate. Because all the required circuitry is manufactured on a single chip, SoC solutions are less expensive, less power intensive, lighter and more compact than multi-chip equivalents. The compromise with such SoC sys- tems is often a slower processor speed and the inability to upgrade and extend, e.g., by adding/replacing graphics, audio or other expansions. The development of SoC products stimulated the use of fully fledged computers in all kinds of devices, not only mobile phones. This led to the rise of embedded systems, systems with one or more computers embedded within them that control such systems. Because all these devices have the ability to communicate, often wirelessly, over the internet, they are sometimes referred to as the IoT (Internet of Things). The Raspberry Pi (RPi or Pi for short) originally used the Broadcom BCM 2835, which is a key example of a SoC. Having undergone several evolutions since the 169 © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 J. F. Groote et al., Logic Gates, Circuits, Processors, Compilers and Computers, https://doi.org/10.1007/978-3-030-68553-9_8