The glossary contains terms and acronyms that are used in this document.

Application Programming Interface (API)

A language and message format used by an application program to communicate with an operating system, application, or other service.


Attribute Protocol (ATT)

“The attribute protocol allows a device referred to as the server to expose a set of attributes and their associated values to a peer device referred to as the client.” Bluetooth Core Specification, Version 5.1, Vol 3, Part F, Section 1.1


Cortex Microcontroller Software Interface Standard (CMSIS)

A vendor-independent hardware abstraction layer for the Cortex®-M processor series that defines generic tool interfaces.


Device Firmware Update (DFU)

A mechanism for upgrading the firmware of a device.


Floating-Point Unit (FPU)

A part of a CPU specially designed to perform operations on floating point numbers.


Generic Access Profile (GAP)

“The Bluetooth system defines a base profile which all Bluetooth devices implement. This profile is the Generic Access Profile (GAP), which defines the basic requirements of a Bluetooth device.” Bluetooth Core Specification, Version 5.1, Vol 1, Part A, Section 6.2


Generic Attribute Protocol (GATT)

“Generic Attribute Profile (GATT) is built on top of the Attribute Protocol (ATT) and establishes common operations and a framework for the data transported and stored by the Attribute Protocol.” Bluetooth Core Specification, Version 5.1, Vol 1, Part A, Section 6.4


Human Interface Device (HID)

Type of a computer device that interacts directly with, and most often takes input from, humans and may deliver output to humans. The term "HID" most commonly refers to the USB-HID specification.


Integrated Circuit (IC)

A semiconductor chip consisting of fabricated transistors, resistors, and capacitors.


Link Layer (LL)

“A control protocol for the link and physical layers that is carried over logical links in addition to user data.” Bluetooth Core Specification, Version 5.1, Vol 1, Part A, Section 1.2


Low-Noise Amplifier (LNA)

In a radio receiving system, an electronic amplifier that amplifies a very low-power signal without significantly degrading its signal-to-noise ratio.


Logical Link Control and Adaptation Protocol (L2CAP)

“Provides a channel-based abstraction to applications and services. It carries out segmentation and reassembly of application data and multiplexing and de-multiplexing of multiple channels over a shared logical link.” Bluetooth Core Specification, Version 5.1, Vol 1, Part A, Section 1.2


Main Stack Pointer (MSP)

The default stack pointer. By default, the nRF52 has a shared call stack for the application and the SoftDevice, managed by the MSP.


Man-in-the-Middle (MITM)

A man-in-the-middle attack is a form of eavesdropping where communication between two devices is monitored and modified by an unauthorized party who relays information between the two devices giving the illusion that they are directly connected.


Memory Watch Unit (MWU)

A peripheral that can be used to generate events when a memory region is accessed by the CPU.


Power Amplifier (PA)

A device used to increase the transmit power level of a radio signal.


Programmable Peripheral Interconnect (PPI)

Enables peripherals to interact autonomously with each other using tasks and events independent of the CPU.


Process Stack Pointer (PSP)

A separate stack pointer that can be used for application threads. This is an optional configuration, but it may be required if using an RTOS.


Qualified Design Identification (QDID)

A unique identifier assigned to a design that has completed Bluetooth® Qualification.


Quality of Service (QoS)

A module in the SoftDevice that is dedicated to providing various signal quality measurements. The application can use this data to estimate the quality of received signal.


Software Development Kit (SDK)

A set of tools used for developing applications for a specific device or operating system.


SoftDevice Manager (SDM)

A SoftDevice component that controls the SoftDevice state and configures the behavior of certain core functionality.


Security Manager (SM)

Provides means for bonding devices, encrypting and decrypting data, and enabling device privacy.


Security Manager Protocol (SMP)

A protocol used for pairing and key distribution.


System on Chip (SoC)

A microchip that integrates all the necessary electronic circuits and components of a computer or other electronic systems on a single integrated circuit.


Supervisor Call (SVC)

Generates a software exception in which access to system resources or privileged operations can be provided.