This is a living glossary of terms and acronyms encountered in the embedded world 

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

0-9

  • 3A: Auto-focus, Auto-exposure, and Auto white-balance. (cameras)
  • 3PL: Third-party logistics

A

  • A-GPS: Assisted GPS
  • AA: Active alignment (referring to camera modules)
  • ABI: Application-binary interface
  • Abstract class: a class that cannot be directly instantiated
  • Abstract data type: a data type defined for a specific domain or application
  • Abstract interface: a set of public procedures that are defined for an abstraction but are not implemented
  • Abstraction: a simplified or idealized representation of a module or system
  • AE: Auto-exposure
  • AF: Autofocus
  • AFC: Audio-frequency choke
  • AOI: Automated optical inspection, area of interest
  • AP: Application processor OR access point (wifi)
  • API: Application programming interface.
  • ASIC: Application-specific integrated circuit. A microchip designed for a special application.
  • Assertion: a special conditional expression used to verify program values or states at points of execution
  • ATS: Automated test system, application test suite, Company: Automated Tooling Systems
  • AWB: Auto-white balance (balances colors on cameras)

B

  • B2B: Board-to-board connector
  • BER: Bit error rate, a measure of performance of digital communications
  • BJT: Bipolar junction transistor
  • BLE: Bluetooth low-energy
  • BMS: Battery Management System, any system that manages a rechargeable battery and protects it from operating outside of safe conditions
  • BMU: Battery Management Unit, alternative term for a BMS
  • Boost: Takes input voltage and increases it
  • BSP: Board support package. A software layer containing hardware-specific drivers and other code.
  • BT: Bluetooth
  • BTLE: Same as BLE. Bluetooth Low Energy
  • BU: Bringup
  • Buck: Takes input voltage and reduces it

C

  • CA: Chromatic aberration, referring to a camera
  • CCC: Code change control, a software development process
  • CCM: Color correction matrix
  • CI: Continuous integration. Testing every source code commit to make sure it builds properly.
  • CISC: Complex instruction set computer
  • CM: Contract Manufacturer
  • CMF: Color, material, finish (ID, describes a design)
  • COB: Close of business, chip on board
  • COGS: Cost of goods sold
  • Cortex-A: ARM processor family. Application processors with increased capabilities, typically able to run a full operating system such as Linux.
  • Cortex-M: ARM processor family. Smallest and lowest power processors available by ARM.
  • CPK: Complex process capability. A statistical measurement of a process's ability to produce output within the specified limits.
  • critical section: A portion of code that must be executed by only one thread at a time.
  • CTB: Clear to build
  • Current Sink: A "current sink" means that current is flowing into a pin, node, or signal.
    • For digital IO, a current sink provides the ground connection to the load.
  • Current Source: A "current source" is the opposite of a current sink: the current is flowing out of a pin, node or signal.
    • For digital IO, a current source provides the voltage source to the load.
  • CV: Contrast value (camera)
  • Cycle Time: a metric for how long a process takes
    • With manufacturing, cycle time can be reported for each stage of the manufacturing process or for the overall time a unit spends on the production line

D

  • Descriptor: An abstract identifier used to access a file, socket, or other system resource.
  • DFM: Design for manufacturing
  • DFU: Device Firmware Upgrade
    • Generally: The mode for USB products where there is no firmware or software on the device, before any install OR it thinks there is no software (erased device)
    • USB Specific: a vendor- and device-independent mechanism for upgrading the firmware of USB devices with improved versions provided by their manufacturers, offering (for example) a way for firmware bugfixes to be deployed.
  • dynamic shared library, dynamic library, DLL: A binary executable that is loaded dynamically into an application’s process space rather than linked statically as part of the application binary.
  • DIP: Dual In-line Package
  • DOA: Dead-on-arrival. Usually refers to new software versions not working or new boards having a flaw. This flaw is often catastrophic and renders the software/hardware unusable.
  • DOE: Design of experiments. Commonly used to mean "experiment"
  • DMM: Digital Multi-meter
  • DQ / DQ'd: Disqualify or disqualified
  • DSP: Digital signal processor
  • DUT: Device under test
  • DVT: Design validation & Test (production stage)

E

  • EABI: Embedded ABI (application-binary interface). An ARM family of ABIs for embedded operating systems. One of the "subABIs" is GNU EABI, for Linux.
  • ECN: Engineering Change Note (aka ECO)
  • ECO: Engineering Change Order (aka ECN)
  • eDP: Embedded Display Port, a standard for communicating with hardware displays
  • EE: Electrical engineer[ing]
  • eFPGA: embedded FPGA (Field programmable gate array)
  • EHCI: Enhanced Host Controller Interface, a controller standard in USB 2.0
  • EIS: External image stabilization (camera)
  • EMI: Electro-magnetic interference
  • EMMC: Embedded multi-media controller
  • EOF: Cameras - End of Frame
  • ESD: Electro-static discharge
  • EVT: Engineering validation and test (production stage)

F

  • FA: Failure analysis
  • FAI: First article inspection. Measuring samples and comparing them to the specs/drawings.
  • FASY: Final Assembly
  • FATP: Final assembly, test, and packout. Follows SMA/SMT
  • FCT: Functional & Connectivity Testing. Checks MLB assembly.
  • FET: Field-effect transistor
  • FF: Form factor [enclosure] - actual product enclosure
  • FFC: Flat flexible cable.
  • FFT: Fast Fourier transform
  • First-pass Yield: Yield calculation without including units that went through a repair cycle
  • Flex: Refers to a flexible printed circuit. Also known as FPC.
  • Floating: A signal is said to be "floating" when its state is indeterminate, meaning that it is neither connected to VCC or to ground
    • The signal's voltage will "float" to match the residual voltage.
    • The term "floating" is often used interchangeably to describe a pin which is in the high-impedance state.
  • FOD: Foreign objects & debris. E.g. dust in a camera module or metal chaff in a sealed box.
  • FPC: Flexible printed circuit. Commonly known as a Flex
  • FPGA: Field-programmable gate array
  • FPU: Floating-point unit
  • FPY: First pass yield
  • FQC: Final quality control
  • Framework: A set of cooperating classes that make up a reusable design for a specific class of software
  • FW: Firmware

G

  • GMSL: gigabit multimedia serial link
  • GND: Abbreviation for "ground"
    • The reference point in an electrical circuit from which voltages are measured
    • The common return path for electric current
    • Direct physical connection to the earth (aka "Earth Ground")
  • GPIO: General purpose IO. A pin on a chip that can be manually controlled by software for any generic purpose. Contrasts specialized pins, like I2S, I2C, SPI, signals.
  • GRR/GR&R: Gage repeatability and reproducibility.
  • GSM: Global supply manager

H

  • Hardware Dependent Software: the part of an OS that varies across hardware platforms. Similar in concept to a BSP.
  • HCI: Host controller interface (Bluetooth, USB), Human-computer interaction (interface design)
  • HDS: Hardware dependent software
  • High Drive (GPIO): High-drive GPIO are push-pull pins that are capable of providing more current than typical pins.
    • While your must check each chip's datasheet to understand the current capacity of your pins, typical push-pull GPIO can source/sink around ±8mA, while a high-drive pin can source/sink up to ±40mA.
  • High-Z, Hi-Z: High-impedance
  • High-impedance: a floating input with no pull-up or pull-down resistor.
    • When a line is put into a high-impedance state, the output is effectively removed from the circuit
    • This allows multiple circuits or devices to share the same output lines and is commonly utilized to implement communication busses
  • Hot bar: Method of installing flexes to MLBs.
  • HPC: High-performance computing

I

  • I2C: Inter-IC Communication. Electronic protocol using two wires to talk to a chip.
  • I2S: Inter-IC Sound. Electronic protocol used to transfer audio data (digital mics, codecs, speakers)
  • IC: Integrated circuit
  • ICD: Interface control document
  • ICT: In-circuit testing. Checks MLB assembly.
  • ID: Industrial design
  • IDL: Interface design language
  • IL: Imprint lithography
  • IMU: Inertial Measurement Unit. Accelerometer, gyroscope, etc.
  • IO, I/O: Input/output.
  • IoT: Internet of things
  • IP: Intellectual property
  • IP core, IP block: A semiconductor intellectual property core. A reusable unit of logic, cell, or integrated circuit layout design that is the intellectual property of one party. Other designers will licenses these blocks for use in their own chips.
  • IPC: Inter-process communication
  • ISA: Instruction-set architecture
  • ISP: Image signal procssor
  • IQ: Image quality
  • IQC: Incoming quality control

J

  • JIT: Just-in-time

L

  • LOC: Lines of code
  • LOE: Level of effort
  • Loopers: Units that enter into the repair/return cycle repeatedly
  • LSB: Least significant bit
  • LT, L/T: Lead-time. How long it takes to get a part made/shipped.
  • LUT: Look-up table
  • LVDS: Low-voltage differential signaling. When used in the context of hardware displays, it refers to FPD-Link, a hardware standard for communicating with displays.

M

  • MAC: Media access control. Refers to an address.
  • MARTE: Modeling and Analysis of Real-Time Embedded Systems. A UML profile (UML extension) focused on concepts for real-time embedded systems.
  • MCA: Multi-core association
  • MCAPI: Multicore communications API, by the MCA (Multi-core Association)
  • MCO: Mechanical Control Outline
  • MCU: Main control unit. aka MLB or motherboard.
  • ME: Mechanical Engineer
  • MES: Manufacturing Execution System. AKA Shop floor system
  • Mfg: Manufacturing
  • MIH: Material in-house. Quantity on hand.
  • MIL: Master issues list
  • MIPI: Mobile Industry Processor Interface. A global, open membership organization that develops hardware interface specifications for the mobile ecosystem.
  • MIPI CSI, MIPI Camera: MIPI Camera Serial Interface. A hardware standard for communicating with IC camera sensors.
  • MIPI DSI: MIPI Display Serial Interface. A hardware standard for communicating with displays.
  • MIPI Touch: A hardware standard for communicating with touch sensors embedded in displays
  • MLB: Main logic board - AKA motherboard
  • MMU: Memory management unit
  • MOF: Middle of Frame
  • MOQ: Minimum order quantiy. Minimum number of parts that can be ordered from a supplier.
  • MOSFET, MOS-FET: Metal-oxide-semiconductor field-effect transistor
  • MP: Mass-production (production stage)
  • MPM: Material PM
  • MPN: Manufacturer Part Number.
  • MPS: Master Production Schedule
  • MRAPI: Multicore resource management API, by the MCA (Multi-core Association)
  • MSB: Most significant bit
  • MTAPI: Multicore task management API, by the MCA (Multi-core Association)
  • MTBF: Mean time between failures
    • The predicted elapsed time between failures of a mechanical/electronic system during normal operation.
    • Used for repairable systems
  • MTTF: Mean time to failure
    • Denotes the expected time to failure for a non-repairable system
  • mutex: A lock that provides mutually exclusive access to a shared resource
    • A mutex lock can be held by only one thread at a time
    • Attempting to acquire a mutex held by a different thread puts the requesting thread to sleep until the lock can be acquired

N

  • NED: Non-enclosed device. Usually a fully-functional device without a normal form factor enclosure.
  • NG: Not good
  • NPI: New product introduction
  • NPN: a type of bipolar junction transistor consisting of a layer of P-doped semiconductor between two N-doped layers
  • NTF: No trouble found
  • NTBF: Not to be fixed
  • NVIC: Nested vector interrupt controller. Present on some ARM cores, such as Cortex-M3

O

  • OC: Optical center
  • OCM: Original Contract Manufacturer
  • ODM: Original design manufacturer. Makes a product to spec that's rebranded and sold by another company.
  • OMM: Optical measurement machine
  • OOBA: Out of box audit. Sampling of post-packout units to verify cosmetics, manufacturing process, functionality of devices.
  • OTP: One Time Programmable. Refers to chip settings that can only be programmed one time, e.g. chip fusing, PMIC settings.
  • Open-collector (GPIO): Refers to a current sink on a transistor output. Functionally the same as an "open drain".
  • Open-drain (GPIO): Refers to a current sink on a FET output.
    • Unlike push-pull, an open-drain output can only sink current.
    • The output has two states: low and high-impedance.
    • In order to achieve a logical high output on the line, a pull-up resistor is used to connect the open-drain output to the desired output voltage level.
  • Overall Yield: Yield calculation including units that were successfully repaired
  • OQC: Outgoing quality control

P

  • Packout: Manufacturing stage where shipping software is installed and the device is packaged.
  • PCB: Printed circuit board
  • PCBA: Printed circuit board assembly
  • PD: Product design, pull-down (resistor)
  • PE: Process Engineer (Mfg), Principle Engineer (Engineering)
  • PFOL: Product first offline. Review first production units onsite at company location.
  • PHY: Indicates a "physical" layer, or the actual electrical connection and encoding hardware of a communication protocol
  • PLL: Phase-locked loop
  • PLM: Project lifecycle management. The process of managing the entire lifecycle of a product from inception, through engineering design and manufacture, to service and disposal of manufactured products.
  • PM: Program/project manager
  • PMBus: Power Management Bus
  • PMIC: Power management IC
  • PMU: Power management unit
  • POC: Proof-of-concept
  • PN, P/N: Part number
  • PNP: A type of bipolar junction transistor consisting of a layer of N-doped semiconductor between two-layers of P-doped material
  • Post-snap: After a form factor unit has been completely closed - assembly is finished.
  • PRQ: Post ramp qualification. A controlled production run done during MP (after ramp) to validate a change prior to converting full production to the new design. Often done to validate new part versions or alternate sources.
  • PSA: Platform-security architecture (ARM concept), pressure-sensitive adhesive
  • PT: Prototype
  • PTS: Camera/Video: Presentation time stamp, playback time stamp.
  • PTZ: Pan, tilt, & zoom (camera)
  • PU: Pull-up (resistor)
  • Pull-down (resistor): Resistors that connect an signal to ground
    • Pull-downs are used to set a default state when the signal is floating
  • Pull-up (resistor): Resistors that connect an signal to VCC
    • Pull-ups are used to set a default state when the signal is floating
  • Push-pull (GPIO): GPIO that has the ability to both source and sink current.
    • With a push-pull GPIO, a transistor connects to VCC or GND to drive a signal high or low.
    • When the output goes low, the signal is actively "pulled" to ground, and when the output goes high it is actively "pushed" to VCC.
  • PVT: Production validation and test (production stage)

Q

R

  • Ramp: Production stage where volumes are increased steadily until they hit MP levels
  • RBOM: Rest of BOM
  • RC: root cause, the primary failure leading to an issue.
  • Reentrant: describes code that can be started on a new thread safely while it is already running on another thread
  • Retest Rate: A calculation which indicates the number of units that initially fail a given process step, but pass upon retesting with no changes made to the unit
  • RFC: Radio-frequency choke
  • RI: Relative illuminance, referring to a lens.
  • RISC: Reduced instruction set computer
  • ROI: Region of interest, return on investment
  • RPC: Remote procedure call
  • RSB: Return Stack Buffer
    • A common prediction structure in modern CPUs, similar to a branch predictor for return instructions
  • RTC: Real-time clock
  • RTFM: Real-time for the masses
  • RTOS: Real-time OS
  • Run loop: An event-processing loop, during which events are received and dispatched to appropriate handlers.
  • RX: Receive

S

  • SCM: Source code management, supply chain management
  • SDHC: SD (as in SD card) High Capacity
  • SDIO: Secure digital input/output. Electronics communication bus.
  • SDXC: SD (as in SD Card) Extended Capability
  • semaphore: A protected variable that restricts access to a shared resource
    • Mutexes and conditions are both different types of semaphore.
  • SERDES: Serializer/Deserializer. A pair of functional blocks commonly used in high-speed communications to compensate for limited input/output. These blocks convert data between serial data and parallel interfaces in each direction.
  • SFC: Shop floor control
  • SFR: Special function register - provides an interface to core and peripheral hardware functionality of a microprocessor or microcontroller. They are commonly mapped into the processor’s address space, similar to RAM
  • SHA: Secure hash algorithms. A family of cryptographic hash functions that are commonly used in computer systems.
  • SIMD: Single-instruction, multiple data
  • SIP: System-in-a-package. A number of integrated circuits enclosed in a single module (package)
  • SKU: Shop Keeping Unit, Stock Keeping Unit. Internally generated part numbers used to keep track of inventory/sales.
  • SMA: Surface mount assembly. Refers to putting parts on a PCB. After SMA, a PCB is referred to as a PCBA.
  • SMT: Surface mount technology. Also refers to the SMA + board testing process as a whole.
  • SN, S/N: Serial Number
  • SoC: System-on-a-chip. A complex processor with peripheral devices included in a single chip package
  • SOF: Cameras - Start of Frame
  • SOM: System-on-module. A board-level circuit that integrates a system function in a single module.
  • SPE: Secure processing environment, an ARM concept
  • SPI: Serial peripheral interface [communication bus]
  • SPL: Software Product Line
  • SRP: Stack resource policy, a scheduler implementation
  • SVE: scalable vector extension
  • SysML: Systems Modeling Language, a UML extension

T

  • TAB: Tape automated bonding
  • T/C: Thermal cycling
  • TEE: Trusted execution environment (ARM concept)
  • TIL: Test issues list
  • Thermocouple: An electronic component used to sense temperature
  • Throughput Yield: the probability that any unit will make it through the entire manufacturing process without failing. Calculated by multiplying the first-pass yield of each stage
  • Tri-state (logic): Most modern GPIO lines are implemented as a tri-state buffer. This means that the GPIO line can effectively assume three values: logical 0 (connection to ground), logical 1 (connectin to VCC), and High-impedance (also called "floating", "Hi-Z", "tri-stated")

  • TX: Transmit

U

  • UB: Undefined behavior
  • UI: User Interface
  • UML: Unified Modeling Language
  • UN38.3: Certification required for shipping lithium batteries
  • UPH: units-per-hour, a measure of production volume in a given hour of production time
  • UX: User Experience

V

W

  • WH: Warehouse
  • WIP: Work-in-progress
    • In a manufacturing context, units that have not cleared a test stage or cleared the test line can be considered WIP
  • WLP: Wafer-level packaging.
  • WS: Working sample. AKA Prototype

X

Y

Z