Glossary A/D - Analog to Digital. ADC - Analog to Digital converter. BASH - Bourne Again Shell. This is a revision of the Bourne shell. It is the standard GNU (GNU's Not Unix)/Linux command interpreter. CoLinux - means to provide Linux services on a Windows host. Companding - The process of logarithmically encoding and decoding data to minimize the number of bits that must be sent. CPLD (Complex Programmable Logic Device) - Complex Programmable Logic Device. These devices are integrated circuits which can be programmed to implement custom logic circuits. CPP - The GNU (GNU's Not Unix) preprocessor. Cross Compiling - Compiling source code on one platform (e.g. (for example) Linux x86 desktop) for execution on another platform (e.g. (for example) Blackfin). D/A - Digital to Analog. DAC - Digital to Analog converter. DDD - Data Display Debugger. A graphical front-end for command-line debuggers such as gdb. DHCP (Dynamic Host Configuration Protocol) - Dynamic Host Configuration Protocol. A communications protocol that assigns IP addresses to machines when they are connected to the network. DMA (Direct Memory Access) - Direct Memory Access. A way of moving data between system devices and memory in which the data is transferred through a DMA (Direct Memory Access) port without involving the processor. DMA (Direct Memory Access) External Bus (DEB) - A bus that provides a means for DMA (Direct Memory Access) channels to off-chip memory. DRAM - Dynamic Random Access Memory. A type of memory that has to be refreshed periodically to keep from loosing its values. EAB - External Access Bus. A bus mastered by the core memory management unit to access external memory. EBIU (External Bus Interface Unit) - External Bus Controller. A component that provides arbitration between the External Access Bus (EAB) and the DMA (Direct Memory Access) External Bus (DEB), granting at most one requester per cycle. ELF (Executable and Linking Format) - Executable and Linkable Format. The Linux standard binary format. EPROM - Erasable Programmable Read-Only Memory. Memory that retains its programmed values without an external power supply. This memory may be erased by ultraviolet light or an electric signal in the case of Electronically Erasable PROM (EEPROM). Ethernet - A physical layer protocol based on IEEE standards. FFT - Fast Fourier Transform. An algorithm for computing the Fourier transform of a set of discrete data values. Flash Memory - Non-volatile, erasable memory in which erasing can only be done in blocks or for the entire chip. GAS - The GNU (GNU's Not Unix) Assembler, also called AS. GCC (GNU Compiler Collection) - The GNU (GNU's Not Unix) Compiler. GDB (GNU Debugger) - The GNU (GNU's Not Unix) debugger. Glueless - No external hardware is required. GNU (GNU's Not Unix) - GNU (GNU's Not Unix)'s Not Unix. A project of the Free Software Foundation to provide free software for UNIX‑like environments. I/O - A short form of input/output. IDE (Integrated Drive Electronics (hard drives!)) - Integrated Development Environment. This is an application which brings together all the components needed to create programs. Tools such as a source code editor; project tree browsers; and interfaces to compilers, assemblers, and linkers are usually included. IP Address - Internet Protocol Address. A unique 32-bit identifier assigned to a machine connected to a TCP/IP network. IRQ (Interrupt request) - Interrupt Request. A signal sent from a peripheral device to the processor which request that some action, such as processing data from the peripheral, be taken. JRE - Java Runtime Environment. The minimum set of files and utilities that are required to run Java programs. JTAG (Joint Test Action Group - low level interface to cpu) - Joint Test Action Group. A protocol outlining standards in low level hardware access, typically used for debugging. Kernel - The core of an operating system which provides fundamental services such as hardware management and resource allocation. L1 Memory - Level 1 memory. Memory that is directly accessed by the Blackfin core with no intervening memory subsystems. L2 Memory - Level 2 memory. Memory that is at least one level removed from the Blackfin core. L2 memory has a larger capacity than L1 memory, but it requires additional latency to access. LAN - Local Area Network. LD - The GNU (GNU's Not Unix) Linker. Linux - A kernel originally developed by Linus Torvalds which is often combined with various free software and utilities from the GNU (GNU's Not Unix) project to create a non-proprietary UNIX-like environment. MAC (Media Access Control (network interface)) - Multiply / Accumulate. A mathematical operation that multiplies two numbers and then adds a third to get the result. MAC (Media Access Control (network interface)) Address - Media Access Control Address. This is a globally unique 48-bit physical identifier assigned by the manufacturer to an Ethernet device, it is registered with the IEEE. The MAC (Media Access Control (network interface)) address is typically transmitted through the Ethernet frame, it is used by a network to identify know machines. MMR (Memory Mapped Register) - Memory Mapped Register. A specific location in the Blackfin processor's main memory which is used by the processor as if it were a register. MMU - Memory Management Unit. A component of the processor that supports protection and selective caching of memory. Netmask - A set of flags which determine which part of an IP address refers to the network and which part refers to the host range. Orthogonal - The characteristic of being independent. An orthogonal instruction set allows any register to be used in an instruction that references a register. PC - Program counter. A register that contains the address of the next instruction to be executed. PF - Programmable Flag. General purpose input/output pin on the Blackfin processor. PIC - Position Independent Code. Code that uses only relative address and consequently can be run from any memory location. PPI (Parallel Peripheral Interface) - Parallel Peripheral Interconnect. A peripheral on the Blackfin processor used to connect to parallel devices such as A/D and D/A converters. ROM - Read Only Memory. A data storage device manufactured with fixed contents. RTC (Real Time Clock) - Real Time Clock. A Blackfin component that generates timing pules for the digital watch features of the Blackfin processor. S/P-DIF - Sony/Phillips Digital Interface. A protocol for sending and receiving digital audio. SDRAM (synchronous dynamic random access memory (system memory)) - Synchronous Dynamic Random Access Memory. A form of DRAM that includes a clock signal with its other control signals. This clock signal allows SDRAM (synchronous dynamic random access memory (system memory)) devices to support burst access modes that clock out a series of successive bits. SMP - Symmetric Multiprocessing. A system architecture in which two or more processors, each being able to run any task including kernel tasks, share the processing load. SPI (Serial Peripheral Interface) - Serial Peripheral Interface. A synchronous serial protocol used to connect integrated circuits. SPORT (synchronous high speed serial port) - Serial Port. A high speed synchronous input/output device on the Blackfin processor. SRAM (synchronous random access memory (L1 memory)) - Static Random Access Memory. Fast read/write memory that does not require periodic refreshing. Subnet - The network portion of an IP address. TCP / IP - Transmission Control Protocol / Internet Protocol. These protocols form the bases of all Internet communications. TFTP (Trivial File Transfer Protocol) - Trivial File Transfer Protocol. This protocol implements very basic network file transfer functionality. It is often used to load a boot image. UART (universal asynchronous receiver/transmitter) - Universal Asynchronous Receiver Transmitter. A module that contains both the receiving and transmitting circuits required for asynchronous serial communication. uClibc - This is the uClinux embedded C library. UNIX - A multi-user, portable operating system originally developed by Bell Labs.