This glossary section defines some of the terms and acronyms used in the Ambiq products and the related terminologies used in the industry. These definitions are for reference and personal use only.
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

2.4 GHz ISM

Industrial, Scientific, and Medical band for Bluetooth BLE

4s1p (4 series cells and 1 parallel cell)

Four AA batteries are connected as 4s1p.

50 Ω impedance (fifty Ohms)

The standardized RF impedance.


A protocol that allows power constrainted IoT devices to access the TCP/IP internet directly.


A (amp)

A unit of electrical current.

A2DP (Advanced Audio Distribution Profile)

Part of the Bluetooth protocol. It's the most common protocol for wireless audio streaming, designed to unidirectionally transfer an audio stream in up to two-channel stereo from one device to another. A2DP does not handle TWS and will send the stream to one device, which then splits the channels to two speakers that are connected by a wire.

AC vs DC

alternating current vs. direct current

ACAP (adaptive compute acceleration platforms)

Xilinx new Versal FPGAs.

ACF (auto correlation functions)

Also known as serial correlation, is the correlation of a signal with a delayed copy of itself as a function of delay.


Analog-to-Digital Converter


Acoustic Echo Cancellation (algorithm)

AES (Advanced Encryption Standard)

A specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001.

AES-NI (Advanced Encryption Standard New Instructions)

An extension to the x86 instruction set architecture for microprocessors from Intel and AMD proposed by Intel in March 2008.


all flash array (storage)


AMBA High-performance Bus


Advanced High-Performance Bus Access Port


Assistive Listening Systems for hearing aids.

ALU (Arithmetic Logic Unit)

A fundamental building block of many types of computing circuits, including CPU, FPG, and GPU. It's a combinational digital electronic circuit that performs arithmetic and bitwise operations on integer binary numbers, which is in contrast to a floating-point unit (FPU) that operates on floating point numbers.

AMA (Alexa Mobile Accessory)

Protocol for Bluetooth accessories.

AMBA (Advanced Microcontroller Bus Architecture)

An open-standard, on-chip interconnect specification for the connection and management of functional blocks in system-on-a-chip (SoC) designs. It facilitates development of multi-processor designs with large numbers of controllers and components with a bus architecture. AMBA is a registered trademark of Arm.

ANC (Active Noise Control)

Also known as noise cancellation, or active noise reduction (ANR), is a method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first.

ANSI (American National Standards Institute)

A private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.

ANT (Adaptive Network Topology)

ANT defines a wireless communications protocol stack that enables hardware operating in the 2.4 GHz ISM band to communicate by establishing standard rules for co-existence, data representation, signalling, authentication, and error detection. It is conceptually similar to Bluetooth low energy, but is oriented towards usage with sensors. ANT is a proprietary (but open access) multicast wireless sensor network technology designed and marketed by ANT Wireless (a division of Garmin Canada). ANT+ is lower power standard ANT.


The technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution signal at a lower resolution. Anti-aliasing means removing signal components that have a higher frequency than is able to be properly resolved by the recording (or sampling) device.


Angle of Arrival


Angle of Departure


Advanced Peripheral Bus


AI Processor Unit


Annual Recurring Revenue (accounting)


Audio Streaming for Hearing Aids

ASR (automatic speech recognition)

Also known as speech recognition to text (STT), is an interdisciplinary subfield of computer science and computational linguistics that develops methodologies and technologies that enable the recognition and translation of spoken language into text by computers.


Asynchronous Sampling Rate Converter


An AMBA bus protocol for trace data. The ATB is a common bus used by the trace components to pass trace data in a system in a data-agnostic format. A trace device can use an ATB to share CoreSight capture resources.


Microcontrollers by Atmel, acquired by Microchip.


AXI (Advanced eXtensible Interface)

Part of the ARM Advanced Microcontroller Bus Architecture 3 (AXI3) and 4 (AXI4) specifications. It is a parallel high-performance, synchronous, high-frequency, multi-master, multi-slave communication interface, mainly designed for on-chip communication.

BERT (Bidirectional Encoder Representations from Transformers)

A deep learning algorithm related to natural language processing. It helps a machine understand what words in a sentence mean, but with all the nuances of context.


ball grid array

BIB (Burn-in Board)

Burn in Board is a printed circuit board which functions as a jig in the Burn-in process. The Burn-in Board is used as part of the ASIC reliability testing process during which components are stressed to detect failures. Burn in Boards consist of sockets to accommodate the tested ASICs and are designed to withstand the hot temperatures during tests.

Bit blit (bit block transfer)

A data operation commonly used in computer graphics in which several bitmaps are combined into one using a boolean function.

BLE (Bluetooth Low Energy)

Also known as Bluetooth 4.0 wireless, personal-area network with short-range low-power consumption.


bit per pixel


Brain Processing Unit


(Bluetooth) Basic Rate/Enchanced Data Rate


bus turnaround

CCATS (Commodity Classification Automated Tracking System)

Commodity Classification Automated Tracking System (CCATS) is an alphanumeric code assigned by the United States Bureau of Industry and Security (BIS) to products that it has classified under the Export Administration Regulations (EAR). Software companies provide the CCATS number because some encryption exports require the exporter to make post-shipment reporting to BIS on a bi-annual basis and the CCATS number is one of the mandatory elements required for reporting.


Convolutional Neural Networks


A portmanteau of coder-decoder. A device or computer program which encodes or decodes a digital data stream or signal.






Configuration Register File

CSP (Chip-Scale Package)

Chip-scale package (CSP) is a dual or multi-layer plastic encapsulated BT-Epoxy type substrate with copper signal and plain layers.


Constant Tone Extension

CVFS (Continuous Voltage Frequency Scaling)

ETA Compute patented technology.

DAP (Debug Access Port)

DP - Debug Port
AP - Access Port


display bus interface

dBm (decibel-milliwatts)

dBm (sometimes dBmW or decibel-milliwatts) is unit of level used to indicate that a power ratio is expressed in decibels (dB) with reference to one milliwatt (mW).

DC (Display Controller)

VDC (video display controller) - an integrated circuit which is the main component in a video signal generator, a device responsible for the production of a TV video signal in a computing or game system.

DDR (Double Data Rate technology)

A computer bus transfers data on both the rising and falling edges of the clock signal: SDR - single data rate QDR - quad data rate

DDR SDRAM (Double Data Rate Synchronous Dynamic Random-Access Memory)

A double data rate (DDR) synchronous dynamic random-access memory (SDRAM) class of memory integrated circuits used in computers.

DET (Detection Error Tradeoff)

A graphical plot of error rates for binary classification systems, plotting the false rejection rate versus false acceptance rate.


device firmware updates


Add white noise to (a digital recording) to reduce distortion of low-amplitude signals. A specification by the Mobile Industry Processor Interface (MIPI) Alliance aimed at reducing the cost of display controllers in a mobile device.

DLA (deep-learning accelerator)

A highly optimized hardware unit in FPGA specializing in accelerating the ternary neural network (TNNs), while the proposed framework can significantly compress the deep neural networks (DNN) parameters down to two bits with little accuracy drop.


direct memory access

DMIC (digital microphone)

Versus AMIC which is analog.


deep neural network

DOA (direction of arrival)

Denotes the direction from which usually a propagating wave arrives at a point, where usually a set of sensors are located. These set of sensors forms what is called a sensory array. Often there is the associated technique of beamforming which is estimating the signal from a given direction.

DPI (Display Pixel Interface)

The interface defined by the Mobile Industry Processor Interface (MIPI), which is used for Active-Matrix LCD displays for handheld devices. It is intended for the display modules in the mobile devices.

DRC (Design Rule Constraints/Checking)

A design rule is a geometric constraint imposed on circuit board, semiconductor device, and integrated circuit (IC) designers to ensure their designs function properly, reliably, and can be produced with acceptable yield. Design rules for production are developed by process engineers based on the capability of their processes to realize design intent.

DSI (Display Serial Interface)

A specification by the Mobile Industry Processor Interface (MIPI) Alliance aimed at reducing the cost of display controllers in a mobile device.


digital signal processor


Data Watchpoint and Trace



error-code correction

ECCN (Export Control Classification Number)

A five character alpha-numeric designation used on the Commerce Control List (CCL) to identify dual-use items for export control purposes. ECCNs are divided into ten broad categories, and each category is further subdivided into five product groups.

ECO (Engineering Change Order)

A document that is used to bring about authorized changes in components and assemblies. They may also be used for changes in documents such as drawings, processes, work instructions and specifications. It can also be used for a modification that will have an effect on a manufactured product or manufacturing process.

EDA (electronic design automation)

A category of software tools for designing electronic systems such as integrated circuits and printed circuit boards.


electronic grade silicon

ENC (Environmental Noise Cancellation)

Similar to active noise cancellation (ANC)


end of conversion

ETM (Embedded Trace Macrocell)

A hardware macrocell that, when connected to a processor, outputs trace information on a trace port. An optional debug component that enables reconstruction of program execution. The ETM is designed as a high-speed, low-power debug tool that ensures the area is minimized, and that gate count is reduced. The ETM provides processor driven trace through a trace port compliant to the ATB protocol. An ETM always supports instruction trace, and might support data trace.


evaluation board

FAR (False Acceptance Rates) vs FRR (False Rejection Rates)

Biometrics. The probability that the system incorrectly matches the input pattern to a non-matching template in the database. The probability that the system fails to detect a match between the input pattern and a matching template in the database.

FB (framebuffer)

A portion of random-access memory (RAM) containing a bitmap that drives a video display. It is a memory buffer containing a complete frame of data. Modern video cards contain framebuffer circuitry in their cores.

FEC (forward error correction)

Bluetooth 5 feature.

FET (field effect transistor)

A type of transistor which uses an electric field to control the flow of current. FETs are devices with three terminals: source, gate, and drain. FETs control the flow of current by the application of a voltage to the gate, which in tern alters the conductivity between the drain and source. An n-channel FET is referred to as a N-FET.

FIDO UAF (Fast IDentity Online Alliance Universal Authentication Framework)

An open industry association that develops and promotes authentification standards to help reduce the world's over-reliance on passwords. FIDO supports a full range of authentification technologies, including biometrics (fingerprint, iris, voice, facial), Trusted Platform Modules (TPM), USB security tokens, embedded Secured Elements (eSE), smart cards, and near field communication (NFC).

FinFET (fin field-effect transistor)

A type of non-planar transistor, or "3D" transistor. A multigate device, a MOSFET built on a substrate where the gate is placed on two, three, or four sides of the channel or wrapped around the channel, forming a double gate structure. These devices have been given the generic name "finfets" because the source/drain region forms fins on the silicon surface. The FinFET devices have significantly faster switching times and higher current density than planar CMOS (complementary metal-oxide-semiconductor) technology.

FIPS (Federal Information Processing Standards)

Publicly announced standards developed by the National Institute of Standards and Technology (NIST) for use in computer systems by non-military American government agencies and government contractors.


Firmware Over-the-Air

FPGA (field-programmable gate arrays)

FPGA vs ASIC (application specific integrated circuits)


Floating Point Unit

FRAM (Ferroelectric RAM)

A random-access memory similar in construction to DRAM but using a ferroelectric layer instead of a dielectric layer to achieve non-volatility. FeRAM is one of a growing number of alternative non-volatile random-access memory technologies that offer the same functionality as flash memory. FeRAM's advantages over Flash include: lower power usage, faster write performance and a much greater maximum read/write endurance (about 1010 to 1014 cycles). FeRAMs have data retention times of more than 10 years at +85°C (up to many decades at lower temperatures). Market disadvantages of FeRAM are much lower storage densities than flash devices, storage capacity limitations and higher cost. Like DRAM, FeRAM's read process is destructive, necessitating a write-after-read architecture.


A frame is a digital data transmission unit in computer networking and telecommunication. In packet switched systems, a frame is a simple container for a single network packet. In other telecommunications systems, a frame is a repeating structure supporting time-division muliplexing. Frames are the basic unit of data transport, of which there are four fundamental types (data, acknowledgement, beacon and MAC command frames), which provide a reasonable trandeoff between simplicity and robustness.

FRC (frame rate control)

A form of temporal dithering which cycles between different color shades with each new frame to simulate an intermediate shade.


False Rejection Rate


Finite State Machine

FTE (Failure to Enroll)

For biometric devices.


Generic Audio Framework

Gamma (or gamma correction)

A nonlinear operation used to encode and decode luminance or tristimulus values in video or still image systems.


gallium nitride substrates

GAP (Generic Access Profile for Bluetooth)

GAP provides a framework that defines how BLE devices interact with each other.

GATT (Generic Attributes Generic Attribute Profile)

GAP defines the general topology for the BLE network stack. GATT describes in detail how attributes (data) are transferred once devices have a dedicated connection.

Gaussian Filter

A filter whose impulse response is a Gaussian function. Gaussian filters have the properties of having no overshoot to a step function input while minimizing the rise and fall time.

GFLOPS (giga floating point operations per second, 109)

A measure of computer performance, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate measure than measuring instructions per second (IPS).


Gaussian frequency-shift keying (vs FSK)

GPIO (General Purpose Input/Output)

A type of pin found on an integrated circuit that does not have a specific function.


Graphic Processing Unit

GUI (Graphical User Interface)

A form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, instead of text-based user interfaces, typed command labels, or text navigation.

HAL (Hardware Abstraction Layer)

The purpose of the hardware abstraction layer was to allow desktop applications to discover and use the hardware of the host system through a simple, portable, and abstract API, regardless of the type of the underlying hardware, such as a GPIO HAL interface.

HAST (Highly Accelerated Temperature/Humidity Stress Test)

It was developed as a shorter alternative to Temperature Humidity Bias (THB) Testing. If THB testing takes 1000 hours to complete, HAST results are available within 96-100 hours.

HCI (host controller interface)

A register-level interface that enables a host controller for USB or IEEE 1394 hardware to communicate with a host controller driver in software.

HFRC (high frequency RC oscillator)

Versus LFRC - low frequency RC (resistors and capacitors)


High Performance Computing

HRNG (hardware random number generator)

Or TRNG, true random generator, a device that generates random numbers from a physical process, rather than by means of an algorithm.

HTOL (High-Temperature Operating Life)

A reliability test applied to integrated circuits (ICs) to determine their intrinsic reliability. This test stresses the IC at an elevated temperature, high voltage and dynamic operation for a predefined period of time. The IC is usually monitored under stress and tested at intermediate intervals. This reliability stress test is sometimes referred to as a "lifetime test," "device life test," or "extended burn in test" and is used to trigger potential failure modes and assess IC lifetime.

ISAT (inductor saturation current)

Inductor saturation current (ISAT) is the current where the inductance drops by a certain percentage, and is determined by the inductor's core size for a given core material and construction.

I2S (Inter-IC Sound Bus)

Allows serial transfer of full duplex streaming data, usually streaming audio, between DSP and an external I2S peripheral such as an audio codec.


Integrated Development Environment


Institute of Electrical and Electronics Engineers

Impedance Matching (input impedance, output impedance)

The practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source to maximize the power transfer or minimize signal reflection from the load.

IOM (Integrated Object Model)

Provides distributed object interfaces to base SAS software features such as the procedural scripting language, data, file system, results content, and formatting services. IOM enables you to use industry-standard languages, programming tools, and communication protocols to develop client programs that access these services on IOM servers.

IOMMU (input-output memory management unit)

A memory management unit (MMU) that connects a direct-memory-access-capable (DMA-capable) I/O bus to the main memory.

ISA (Instruction Set Architecture)


ISO (International Organization for Standardization)

An international standard-setting body composed of representatives from various national standards organizations.

ISR (interrupt service routine)

A special block of code associated with a specific interrupt condition, initiated by hardware, software interrupt instructions, or software exceptions to implement device drivers or transitions between protected modes of operations, such as system calls.

ITM (Instrumentation Trace Macrocell)

Versus ETM (Embedded Trace Macrocell). Hard real-time debugging requires close interaction with the processor. Tracing provides a chronological picture of a system's inner workings up to, starting from, or in the vicinity an event, mainly to guide a human in understanding a faulty program, providing a lightweight, nonintrusive way to collect debug trace output.

JTAG (Joint Test Action Group)

An IEEE group that is focused on silicon chip testing methods. Many debug and programming tools use a Joint Test Action Group (JTAG) interface port to communicate with processors, and verify design and test printed circuit board after manufacture.

ksps (kilo sample(s) per second)

ksps - kilo (thousands) of samples per second
sps - samples per second
Msps - mega (millions) samples per second

KWD (key word detection)

Detects from the sound/voice for a designated keyword to determine whether to take action.


L2CAP (Logical Link Control and Adaptation Protocol Layer)

Acts as a protocol multiplexing layer. It takes multiple protocols from the upper layers and places them in standard BLE packets that are passed down to the lower layers beneath it.


Low Complexisty Communications Codec

LDO (low drop-out regulator)

A DC linear voltage regulator that can regulate the output voltage even when the supply voltage is very close to the output voltage.


light-emitting diode


low-frequency oscillator


link layer

LLC (logical link control)

The logical link control (LLC) data communication protocol layer is the upper sublayer of the data link layer (layer 2) of the seven-layer OSI model. The LLC sublayer acts as an interface between the media access control (MAC) sublayer and the network layer.

LNA (low-noise amplifiers)

An electronic amplifier that amplifies a very low-power signal without significantly degrading its signal-to-noise ratio.

LTE-M or LTE-MTC (machine-type communications)

One of three new standards, along with NB-IoT, from the cellular industry allowing devices that operate on carrier networks to be less expensive and more power efficient.


mA (milliampere)

Compared to μA (micro-amp).

MAC (Multiply-Accumulate; Medium or Media Access Control)

IEEE 802 LAN/MAN standards. In digital signal processing, the MAC operation is a common step that computes the product of two numbers and adds that product to an accumulator. The hardware unit that performs the operation is known as a MAC. 1 MMAC/s is equivalent to 2 MOPS (1 MAC is 2 operation).

mAH (milliamps per hour)

maH is battery power, the more the merrier. MHz (megahertz) is the processor speed, the higher the better.


molded array process ball grid array

MC (Monte Carlo Method)

A broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deterministic in principle. They are often used in physical and mathematical problems and are most useful when it is difficult or impossible to use other approaches. Monte Carlo methods are mainly used in three problem classes: optimization, numerical integration, and generating draws from a probability distribution.


Mix (or Module) Development Kit


MicroElectro Mechanical System

MIO or MIMO (multi-input/output)

A practical technique for sending and receiving more than one data signal simultaneously over the same radio channel by exploiting multipath propagation. A method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation.


millions of instructions per second

MISO (master in, slave out)

The device that generates the clock signal is called the master. MOSI and MISO are the data lines. SPI interfaces can have only one master and can have one or multiple slaves.


Memory Management Unit



MOPS (mega operations per second)

Millions of operations per second versus GOPS (Giga Operations per Second) and TOPS (Tera Operations per Second).

MOS (metal-oxide-silicon transistor) or MOSFET (metal-oxide-semiconductor field-effect transistor)

A type of insulated-gate field-effect transistor (IGFET) that is fabricated by the controlled oxidation of a semiconductor, typically silicon. The voltage of the covered gate determines the electrical conductivity of the device; this ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals.

MOSI (master out, slave in)

The device that generates the clock signal is called the master. MOSI and MISO are the data lines. SPI interfaces can have only one master and can have one or multiple slaves.


MicroProcessor Unit or Memory Protection Unit

MRAM (magnetoresistive random-access memory)

A type of non-volatile random-access memory which stores data in magnetic domains.


Multi-bit SPI (Serial Peripheral Interface)


mega (millions) samples per second

MTJ (Magnetic Tunnel Junctions)

A component consisting of two ferromagnets separated by a thin insulator. If the insulating layer is thin enough (typically a few nanometres), electrons can tunnel from one ferromagnet into the other.

MUX (multiplexer)

Also known as a data selector, MUX is a device that selects between several analog or digital input signals and forwards it to a single output line.




nA (nanoampere)

One thousand millionth (10-9) of an ampere (amp, A). 1 nA = 1,000,000 mA.


Narrowband IoT


Neural Decision Processors

NF (noise figure)

Measures of degradation of the signal-to-noise ratio (SNR), caused by components in a signal chain. It is a number by which the performance of an amplifier or a radio receiver can be specified, with lower values indicating better performance. The noise figure is simply the noise factor expressed in decibels (dB).

NFC (Near-Field Communication)

Popular as a contactless communication between mobile devices, NFC is used to send information without physical device connection.


no fault found


near-field magnetic induction


networking interface card


Non Maskable Interrupt


Neural Processing Unit


Neural Sensor Processor


Nested Vectored Interrupt Controller


Non-Volatile Memory (device)


OCR (optical character recognition)

Part of pattern recognition.

OCV (On-Chip Variation)

A recognition of the intrinsic variability of semiconductor processes and their impact on factors such as logic timing. Historically, as well as operating temperature, timing variation was primarily a consequence of subtle shifts in manufacturing conditions that would lead to ICs from one batch of wafers being 'slow' or 'fast' relative to nominal estimates. If the design passed these two tests, the chip could be considered to have met its timing constraints.

OPCG (On-Product Clock Generator)

It is helpful in generating high speed clock pulses for speed testing.


Versus QPI (Quad SPI PSRAM)


outsourced assembly and test

OSI Model (Open System Interconnection Model)

A conceptual model that characterises and standardises the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology. Its goal is the interoperability of diverse communication systems with standard communication protocols. The model partitions a communication system into abstraction layers.

OTP (one-time password)

Also known as one-time pin or dynamic password, is a password that is valid for only one login session or transaction, on a computer system or other digital device.

OTP (One-Time Programmable Memories)

A particular type of non-volatile that can be programmed only once, versus MTP (Multiple-Time Programmable), a replacement of Flash for security applications or calibration applications.


PAST (Periodic Advertising Sync Transfer)

Bluetooth 5.1 feature.


printed circuit board

PCM (Pulse-Code Modulation)

A method used to digitally represent sampled analog signals.

PCRAM (Phase Change RAM)

A type of non-volatile random-access memory.

PDM (Pulse Density Modulation or Power Distribution Module)

A form of modulation used to represent an analog signal with a binary signal. In stereo mode, the PDM converts 1-bit stereo pulse density modulated (PDM) bit stream data from external digital microphone into 24-bit pulse-code modulated (PCM) data for base-band processing.

PER (Packet Error Rate)

A method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts.

PGA (Programmable-gain Amplifier)

An electronic amplifier (typically an operational amplifier) whose gain can be controlled by external digital or analog signals. The gain can be set from less than 1 V/V to over 100 V/V. Examples for the external digital signals can be SPI, I2C while the latest PGAs can also be programmed for offset voltage trimming, as well as active output filters. Popular applications for these products are motor control, signal and sensor conditioning.


peripheral interface controller (trademark by Microchip)



PLL (phase-locked loop)

A control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop.

PMD (Photonic Mixer Device)

A new generation of time-of-flight (ToF) cameras that realizes 3-D imaging by measuring the distance to the target pixelwise in parallel without scanning.

PMIC (Power Management IC)

A class of integrated circuits that perform various functions related to power requirements. PMICs are solid state devices that control the flow and direction of electrical power.

PMU (Power Management Unit)

A microcontroller that governs power functions of digital platforms. This microchip has many similar components to the average computer, including firmware and software, memory, a CPU, input/output functions, timers to measure intervals of time, and analog to digital converters to measure the voltages of the main battery or power source of the computer. The PMU is one of the few items to remain active even when the computer is completely shut down, powered by the backup battery.

POR (Power-On Reset)

The power-on reset (PoR) is an electronic device incorporated into the integrated circuit that detects the power applied to the chip and generates a reset impulse that goes to the entire circuit placing it into a known state.

Process corner (a design-of-experiments (DoE) technique)

A DoE technique that refers to a variation of fabrication parameters used in applying an IC design to a semiconductor wafer.

PSRAM (Pseudo Static Random-Access Memory)

PSRAM, or PSDRAM, is a dynamic RAM with built-in refresh and address-control circuitry to make it behave similarly to static RAM (SRAM). It combines the high density of DRAM with the ease of use of true SRAM.


Power supply ripple rejection performance of the LDO (low dropout voltage linear regulators).

PVT variations (Process-Voltage-Temperature variations)

Inter-chip variation which depend largely on external factors like: the ambient temperature; the supply voltage, and the process of that particular chip at the time of manufacturing.

PWM (Pulse Width Modulation)

A method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The main advantage of PWM is that power loss in the switching devices is very low.

QFN (Quad Flat No-lead package)

The most popular semiconductor package today because of four reasons: low cost, small form factor and good electrical and thermal performance.

QFP (Quad Flat package)

A surface-mounted integrated circuit package with "gull wing" leads extending from each of the 4 sides.


Versus OPI (Octal SPI PSRAM)

Qwiic (Qwicc Connect System)

An ecosystem, established by Sparkfun, of special inter-integrated Circuit (I2C) protocol connection system that connect sensors, actuators, shields, and cables that make prototyping faster and less prone to error.

RAN (Radio Access Networks)

Part of a mobile telecommunicadtion system. It implements a radio access technology (RAT). Conceptually, it resides between a device such as a mobile phone, a computer, or any remotely controlled machine and provides connection with its core network (CN). Depending on the standard, mobile phones and other wireless connected devices are varyingly known as user equipment (UE), terminal equipment, mobile station (MS), etc. RAN functionality is typically provided by a silicon chip residing in both the core network as well as the user equipment.

Raster Graphics

a raster graphics or bitmap image is a dot matrix data structure that represents a generally rectangular grid of pixels (points of color), viewable via a monitor, paper, or other display medium.


Rasterisation is one of the typical techniques of rendering 3D models. The task of taking an image described in a vector graphics format (shapes) and converting it into a raster image (a series of pixels, dots or lines, which, when displayed together, create the image which was represented via shapes).

RAT (radio access technology)

The underlying physical connection method for a radio based communication network. Many modern mobile phones support several RATs in one device such as Bluetooth, Wi-Fi, and GMS, UMTS, LTE or 5G NR.

RC circuit (Resistor-Capacitor circuit)

Or RC filter, or RC network, is an electric circuit composed of resistors and capacitors driven by a voltage or current source. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit.

RC Oscillator


RDL (Redistribution Layer)

An extra metal layer on a chip that makes the IO pads of an integrated circuit available in other locations of the chip, for better access to the pads where necessary. Versus "direct bump" which are the two construction types of WLCSP.

RE (Read Enable)

Impact of Read Enable (RE) signal's Duty Cycle Distortion (DCD) must be integrated in NAND to Flash Management Controller (FMC) SI simulation to predict system level performance accurately in multi-die, high performance systems. Assuming 50% duty cycle signal at the input to NAND driver is too optimistic. Both FMC and NAND contribute a portion of duty cycle distortion in the NAND read cycle.

REST API (Representational State Transfer API)

A software architectural style that defines a set of constraints to be used for creating Web services. It's an architectural style for distributed hypermedia systems.


radio frequency


RF front-end

RFID (Radio Frequency Identification)

RFID tags can be used to detect and record such as temperature, movement, radiation levels.

RFIO Impedance

RNG (Random Number Generator)

A device that generates a sequence of numbers or symbols that cannot be reasonably predicted better than by a random chance.

RRAM or ReRAM (Resistive RAM)

A form of nonvolatile storage that operates by changing the resistance of a specially formulated solid dielectric material. ReRAM and other memristor technologies also draw much less power than NAND flash. That makes them currently best suited for memory in sensor devices for industrial, automotive and internet of things (IoT) applications. As the cost of manufacturing for ReRAM and other memristors drops, they become competitive with NAND flash. The higher memory density, faster read and write speeds, and lower power draw are reasons why memristor-based memory technologies are often cited as the logical replacement in applications like solid-state drives (SSDs) and nonvolatile dual in-line memory modules (NVDIMMs).

RSSI (Received Signal Strength Indicator)

A measure of the power level at the receiver. When a device scans for Bluetooth devices, the Bluetooth radio inside the device provides a measurement of the RSSI for each seen device. It's measured in decibels, dBm, on a logarithmic scale and is negative.

RTL (Register-Transfer Level)

A design abstraction in digital circuit design which models a synchronous digital circuit in terms of the flow of digital signals (data) between hardware registers, and the logical operations performed on those signals.

RTL (resistor-transistor logic)

A class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit used.

RTLS (real-time location services)

Using a UWB sensor network, RTLS can track assets carrying UWB tags on a factory floor to about 10cm accuracy.


Real-time Operating System


successive-approximation register analog-to-digital converter


subband codec

SBL (Serial Bootloader)

Serial bootloading is a feature that enables a cc254x device to load into flash an embedded software image from a host processor through a serial interface such as UART or SPI.


Secure Boot ROM


Sleep Clock Accuracy Bluetooth 5.1 field


System Control Register


Software-Defined Network

SDR (Single Data Rate; Software-Defined Radio)

Can accept one command and transfer one word of data per clock cycle. Typical clock frequencies are 66, 100, and 133 MHz. Clock rates up to 200 MHz were available. It operates at a voltage of 3.3 V.


Single Data Rate Synchronous Dynamic Random-Access Memory

SEM (Scanning Electron Microscope)

A type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition of the sample.

SI base units (Internatonal System of Units)

The 7 base quantities: (1) the "second" for time, (2) "the metre" for measurement of length, (3) the "kilogram" for mass, (4) the "ampere" for electric current, (5) the "kelvin" for temperature, (6) the "mole" for amount of substance, and (7) the "candela" for luminous intensity.


Special Interest Group

SIM (Subscriber Identity Module)

An integrated circuit that is intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers).

SIMO Buck (Single-Inductor Multiple-Output Buck Converter)

Compared to traditional multiple DC-DC solutions, a single-inductor multiple-output (SIMO) power converter architecture provides space savings while maintaining high efficiency for extended battery life. By providing multiple outputs through a single inductor, the SIMO architecture, along with the regulator’s low quiescent current, enable the IC to extend battery life for space-constrained, battery-powered electronic products.

SiP (System-in-Package)

A number of integrated circuits enclosed in one or more chip carrier packages that may be stacked using Package on package. like systems-on-chip (SoC) but less tightly integrated and not on a single semiconductor die.

SNR (signal-to-noise ratio)

The power ratio between the signal strength and the noise level.

SOA (safe operating area)

Safe operating area for rechargeable battery.




Sytem on Module

SPI (Serial Peripheral Interface vs. MSPI)

SPI is a flexible interface that balances pin count and bandwidth to maximize overall system performance at a lower cost. To offer increased throughput and support for multi-input/output (MIO) functionality, the interface has been extended to include 2-bit IO and 4-bit IO configurations.

SRAM (Static Random-Access Memory)

A type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed. The term static differentiates SRAM from DRAM which must be periodically refreshed. SRAM is faster and more expensive than DRAM; it is typically used for CPU cache while DRAM is used for a computer's main memory.

SWD (Serial Wire Debugger)

A debug implementation that uses a serial connection between the SoC and a debugger. This connection normally requires a bidirectional data signal and a separate clock signal, rather than the four to six signals required for a JTAG connection.


Serial Wire Viewer



Tightly Coupled Memory

TDM (Time-division Multiplexing)

A method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern. It is a communication process that transmit 2 or more digital signals or analogue signals over a common channel.

TDMA (Time-division multiple access)

A channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots.[1] The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity.

TDP (training data platform)

Manage the labeling of data.


Thermoelectric generator


Each cell has 3 states: -1, 0, or 1

THD+N (total harmonic distorion plus noise)

Usually measured by inputting a sine wave, notch filtering the output, and comparing the ratio between the output signal with and without the sine wave.

TMR (triple modular redundancy)

A fault-tolerant form of N-modular redundancy, in which three systems perform a process and that result is processed by a majority-voting system to produce a single output. If any one of the three systems fails, the other two systems can correct and mask the fault.


trillion operations per second


Tera-Operations per Second per Watt


training processor

TPA (Trace Port Analyzer)

A hardware device that captures trace information that is output on a trace port.

TPIU (Trace Port Interface Unit)

Acts as a bridge between the on-chip trace data, with separate IDs, to a data stream, encapsulating IDs where required, that is then captured by a Trace Port Analyzer (TPA).

TSCTM (Think Silicon Converter)

NEMA|PIX-Presso has a user-friendly UI (User Interface) allowing the developers to identify the suitable image format for a given application scenario. It supports several image formats like 16-bit and 32-bit RGB (with and without transparency), grayscale and transparency-only formats of various sizes, png and jpeg formats as well as Think Silicon’s proprietary and patented formats (TSC4, TSC6 and TSC6A) that offer high compression ratios (4 and 6 bits-per-pixel respectively).

TWS (true wireless stereo)

Two non-wired devices serving as left and right speakers.


TX: Transmit; RX: Receive



Universal Asynchronous Receiver/Transmitter

UBM (under-bump metallurgy (for WLCSP))

The UBM is a stack of different metal layers serving as diffusion layer, barrier layer, wetting layer, and anti-oxidation layer. "


heads-up display


Ultra-High Frequency

ULL (ultra-low leakage))

TSMC's 22 nm options (vs. ULP).

ULP (ultra-low power)

TSMC's 22 nm options (vs. ULL).


Low-speed (1.5 Mbit/s), Full-speed (12 Mbit/s), High-speed (480 Mbit/s), SuperSpeed (SS 5 Gbit/s - USB 3.0), SuperSpeed+ (SS+ 10 Gbit/s - USB 3.2).

UWB (Ultra-Wide Band)

UWB operates by generating short, narrow pulses and can be an attractive option for asset tracking and fleet/inventory management. Apple has disclosed only its AirDrop enhancements based on UWB, but it could also employ UWB in two-factor authentication. Meanwhile, NXP is working with BMW and Volkswagen on next-generation keyless-entry systems; UWB's location accuracy can eliminate the relay attacks used to defeat conventional systems.

VAD (Voice Activity Detector)

Also known as speech activity detection or speech detection, is the detection of the presence or absence of human speech, used in speech processing.


Voltage of Battery


voltage-controlled oscillator


Voltage Comparator GP VCOMP (General Purpose)

Vecto Graphics

SVG, EPS, PDF or AI types of graphic file formats vs. JPEG, PNG, APNG, GIF, and MPEG4.

VLIW (Very Long Instruction Word)

Refers to instruction set architectures designed to exploit instruction level parallelism (ILP). Whereas conventional central processing units (CPU, processor) mostly allow programs to specify instructions to execute in sequence only, a VLIW processor allows programs to explicitly specify instructions to execute in parallel.

VLSI (very large-scale integration)

The process of creating an integrated circuit (IC) by combining millions of MOS transistors onto a single chip.

VoE (Vibration of Effects)

A technology to monitor vibration pattern.

VSWR (voltage standing wave ratio or radio)

A measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide. Impedance mismatches result in standing waves along the transmission line, and SWR is defined as the ratio of the partial standing wave's amplitude at an antinode (maximum) to the amplitude at a node (minimum) along the line.


watchdog timer


Wait for Event


Wait for Interrupts

While Loop

In most computer programming languages, a while loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop can be thought of as a repeating if statement. * for testing current consumption


Wake-up Interrupt Controller

WLCSP (Wafer Level Chip Scale Package)

The technology of packaging an integrated circuit while still part of the wafer, in contrast to the more conventional methold of slicing the wafer into individual circuits (dice) and then packaging them.


wafer-level package




wireless personal area network


wireless sensor networks


XiP (eXecute in Place (operations))

For systems where device size and cost are key, program code can be executed directly from non-volatile memory using an approach known as Execute-in-Place (XiP).


Crystal oscillator


Luma (brightness) component and two chrominance (color) components (U - blue porjection, and V - red project). The ' symbol denotes gamma compression. The Y′UV model defines a color space in terms of one luma component (Y′) and two chrominance components, called U (blue projection) and V (red projection) respectively. "Luminance" means physical linear-space brightness. "Luma" means nonlinear perceptual brightness.

YCbCr (Y: luma; Cb/Cr: blue and red chroma)

A family of color spaces used as a part of the color image pipeline in video and digital photography systems.


Y - luminance, U - blue, V - red



Short-range, low-power wireless standards used for sensing and control, typically used for personal or home area networks, or in a wireless mesh for longer-range networks.