# Glossary

The following abbreviations and terms are used in this documentation:

ACS

analog control system

ADC

analog-to-digital converter

AoA

angle of arrival

AoD

angle of departure

Arm Cortex-M33 processor

processing core that can be used to configure the overall system after initial boot, and is typically used to coordinate the system interaction with external components

ASCC

audio sink clock counter

CC312

Arm TrustZone CryptoCell-312 Security IP

CCIT

Causal Conditional Inference Tree

CID

chip identifier

CM

chip manufacture life cycle state

CMSIS

Cortex Microcontroller Software Interface Standard

CRC

cyclic redundancy check

CS

chip select

DAC

digital-to-analog converter

DM

device manufacture life cycle state

DMA

direct memory access

DNL

differential non-linearity

DSP

digital signal processor

ECC

error correcting code

EH

energy harvesting

EVB

Evaluation and Development Board

FIFO

A section of memory that is treated as a buffer where components that use this memory use pointers to handle data in a first-in, first-out manner.

FOTA

firmware-over-the-air

GAP

generic access profile

GATT

generic attribute profile

GPIO

general-purpose input/output

HCI

host controller interface

HIZ

high impedance

I2C

inter-IC communication protocol

I2S

inter-IC sound protocol

IDAU

implementation defined attribution unit

IRK

identity resolving key (used for generating and resolving the resolvable random private address)

JTAG

joint test action group (developer of IEEE standard 1149.1-1990)

L2CAP

logical link control and adaptation protocol

LDO

low dropout voltage regulator

LIN

local interconnect network

LSAD

low-speed analog-to-digital

LSB

least significant bit

MCU

microcontroller unit

memory block instance

an instance of RAM, ROM, or flash memory

memory bus

a communication system that transfers data between memory or memory-mapped components and the cores that operate on that data

MSB

most significant bit

MUX

multiplexer, selector of one signal from many

NVIC

nested vectored interrupt controller

NVM

non-volatile memory

PCM

pulse code modulation

PLL

phase-locked loop

PMU

power management unit

POR

power-on-reset

PWM

pulse width modulation

RAM

random-access memory

RC32

32 KHz standby RC32 oscillator clock source

RCCLK

24 MHz RC oscillator clock source

RFCLK

48 MHz XTAL clock source

RFFE

radio-frequency front-end

RMA

return to manufacturer (one of the life cycle states)

ROM

read-only memory

RTC

real-time clock

SAR-ADC

successive approximation ADC

SAU

secure attribution unit

SCL

serial clock (part of an I2C bus)

SDA

serial data (part of an I2C bus)

SDAC

simple DAC

SE

secure lifecycle state

SPI

Serial Peripheral Interface

SW

serial wire

SWJ-DP

serial wire and JTAG debug port

TOF

time of flight

TRNG

true random number generator

UART

universal asynchronous receiver-transmitter

VBAT

supply voltage to the system (typically supplied from a battery)

VCO

voltage-controlled oscillator

VDDA

supply voltage for the non-RF analog blocks

VDDC

supply voltage for the digital logic

VDDFLASH

supply voltage powering flash memory

VDDM

supply voltage for the memories

VDDO

supply voltage for the digital I/O pads, including the GPIO and debug port (SWJ-DP) pads

VDDPA

optional supply voltage for the power amplifier from the RF front-end

VDDRF

supply voltage for the RF front-end

VREF

bandgap reference voltage

VREG

regulated reference supply voltage

VSSA

analog ground supply reference

VSSO

ground reference for the digital I/O pads

VSSRF

RF ground supply reference

XTAL

crystal, generally quartz-based

XTAL32K

32 KHz standby XTAL32K clock source