ARM Ltd. designs the ARM (Advanced RISC Machine) series of low-cost, power-efficient, 32-bit microprocessors. More than 10 billion processors featuring an ARM core have been shipped, primarily for use in embedded systems. In fact, 98 percent of the world’s mobile phones contain at least one ARM processor. You can apply ARM architectures to almost any embedded application, from automotive communications protocols to security systems and medical devices.
However, ARM Ltd. does not manufacture or sell any physical chips. Instead, it provides other semiconductor companies with intellectual property (IP) solutions in the form of ARM architecture cores or systems on a chip (SOCs). The licensees of the ARM core can then optimize, customize, and manufacture the IP for their particular use cases or customer requirements. Variations of ARM cores include changing clock frequencies, adding on-chip RAM, or adding an on-chip peripheral such as analog-to-digital converters (ADCs). Examples of ARM licensees include Luminary Micro, NXP, STMicroelectronics, and Texas Instruments.
ARM Ltd. provides a wide range of processor designs depending on the system requirements. Typically ARM offerings are categorized into application-level microprocessors or embedded system microcontrollers.
Comparison of Embedded Processor Types
An application microprocessor (MPU) solution is typically used to create a system similar to a PC, mobile phone, or personal media player running a complex operating system. These processors focus mainly on providing the maximum performance amount and place a lower importance on minimizing power consumption and cost. Another major distinguishing feature of a microprocessor is that the chip itself consists only of a processing unit. The microprocessor must be programmed to communicate with peripherals, such as analog and digital I/O, external to the chip. Embedded hardware engineers must place the peripherals on their board designs to give their microprocessor the ability to communicate to the outside world, and embedded software engineers must develop software to interact with these external peripherals.
Microcontroller (or MCU) solutions are used in real-time systems in automotive, industrial, and networking applications. Microcontroller designs emphasize simplicity and lower processing capabilities in exchange for a low-power, inexpensive price point. The major distinguishing factor between a microcontroller and microprocessor is that many of the peripherals are located on-chip. Peripherals such as analog and digital I/O and networking capabilities are often located on the microcontroller, reducing the complexity of the board design and software communications for hardware and software engineers, respectively.
Another commonly used embedded component is a field-programmable gate array (FPGA). An FPGA is a reconfigurable semiconductor that engineers can use to create custom circuitry defined in software. FPGAs are incorporated in a variety of applications such as high-performance data processing and high-speed control. This performance capability is achieved through the inherently parallel nature of FPGA hardware. FPGAs in embedded systems are often paired with a microprocessor, such as in NI reconfigurable I/O (RIO) products.