Embedded System Terminology -B
| Background Debug Mode (BDM) Components used in debugging an embedded system.BDM components include BDM hardware on the board (a BDM port and an integrated debug monitor in the master CPU), and debugger on the host (connected via a serial cable to BDM port). BDM debugging is sometimes referred to as On-Chip Debugging (OCD). |
| Bandwidth - On any given transmission medium, bus, or circuitry—the frequency range of an analog signal (in hertz, the number of cycles of change per second) or digital signal (in bps, the number of bits per second) traveling through it (as in the case of a bus or transmission medium) or being processed by it (as in the case of a processor). |
| Basic Input/Output System (BIOS) - Originally the boot up firmware on x86-based PCs, now available for many off-the-shelf embedded x86-based boards and a variety of embedded OSes. |
| Battery - A voltage source where voltage is created through a chemical reaction within it. A battery is made up of two metals submerged within a chemical solution, called an electrolyte, that is in liquid (wet cell) or paste (dry cell) form. Basically, the two metals respond with different ionic state after they are exposed to the electrolyte. Wet cells are used in automobiles (car batteries), and dry cells are used in many different types of portable embedded systems (radios, toys, etc.). |
| Baud Rate - The total number of bits per some unit of time (kbits/sec, Mbits/sec, etc.) that can be transmitted over some serial transmission link. |
| Bias - An offset (such as voltage or current) applied to a circuit or electrical element to modify the behavior of the circuit or element. |
| Bidirectional - Describes a type of device or bus that supports two-way data transfers. |
| Big Endian - A method of formatting data in which the lowest-order byte (or bits) are stored in the highest byte (or bits). For example, if the highest-order bits are from left to right in descending order in a particular 8-bit ISA, big endian mode in this ISA would mean that bit 0 of the data would be stored from left to right in ascending order (the value of“B3h/10110011b” would be stored as “11001101b”). In a 32-bit ISA, for instance, where the highest-order bytes are stored from left to right in descending order, big endian mode in this ISA would mean that byte 0 of the data is stored from left to right in the word in ascending order (i.e., the value of “B3A0FF11h” would be stored as “11FFA0B3h”). |
| Binary - A base-2 number system used in computer systems, meaning the only two symbols are a “0” or “1”. These symbols are used in a variety of combinations to represent all data. |
| Binary Semaphore - A type of semaphore with just two states. Often used to guarantee mutual exclusion. |
| Bit Error Rate (BER) - The rate at which a serial communication stream loses and/or transfers incorrect data bits. |
| Bit Rate - The (number of actual data bits transmitted / total number of bits that can be transmitted) * the baud rate of the communications channel. |
| Black-Box Testing - Testing that occurs with a tester that has no visibility into the internal workings of the system (no schematics, no source code, etc.) and is basing testing on general product requirements documentation. |
| Block Started by Symbol (BSS) - BSS is several different things depending on the context and who is asked, including “Block Started by Symbol”, “Block Storage Segment”, and “Blank Storage Space”. The term “BSS” originated from the 1960’s, and while not everyone agrees on what the BSS acronym stands for, it is generally agreed upon that BSS is a statically allocated memory space containing the source code’s uninitialized variables (data). |
| Board Support Package (BSP) - A software provided by many embedded off-the-shelf OS vendors that allow their OSes to be ported more easily over various boards and architectures. BSPs contain the board and architecture-specific libraries required by the OS, and allow for the device drivers to be integrated more easily for use by the OS through BSP APIs. |
| Bootloader - Firmware in an embedded system that initializes the system’s hardware and system software components. |
| Bound Out Processor - A special version of a processor that has some of the internal signals brought out to external pins. |
| Breakpoint - A debugging mechanism (hardware or software), which stops the CPU from executing code. |
| Bridge - A component on an embedded board that interconnects and interfaces two different buses. |
| Burst Mode - The maximum short-term throughput which a device is capable of transferring data |
| Bus - A collection of wires that interconnect components on an embedded board. |
| Busy wait - To waste precious CPU cycles polling. |
| Byte - A byte is defined as being some 8-bit value. |
| Byte code - Byte (8-bit) size opcodes that have been created as a result of high-level source code (such as Java or C#) being compiled by a compiler (a Java or some Intermediate Language (IL) compiler) on a host development machine. It is byte code that is translated by a Virtual Machine (VM), such as: the Java Virtual Machine (JVM) or a .NETCE Compact Framework virtual machine, for example. |
| Byte Order - How data bits and/or bytes are represented and stored in a particular component of a computer system. |
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Related topics:
Embedded System Architecture | Embedded Hardware Architecture | Embedded Software Architecture | Embedded Software Definition | Embedded System Acronyms | Embedded System Symbols
List of topics: Embedded System
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