Glossary
of Computer Programming
and Robotics Terms

ASCII: Acronym for "American Standard Code for Information Interchange". It is widely accepted type of coding where each number and letter have their own eight-bit code. In this system, 32 is space, 65 is "A", 87 is "a".

Assembler: A software development tool that translates human-readable assembly language programs into machine-readable code that the target processor can understand and execute.

Assembly Language: A human-writable form of a processor's native instruction set. In its typical form, each line of assembly code represents a single CPU instruction. The human-readable representation of each opcode is called a mnemonic.

Big-endian: A data representation for a multibyte value that has the most significant byte stored at the lowest memory address. Every processor stores its data in either big-endian or little-endian format. Sun's SPARC, Motorola's 68k, the Java Virtual Machine, and the PowerPC families are all big-endian. Every communications protocol must define the byte order of its multibyte values. TCP/IP uses big-endian representation.

Breakpoint: A location in a program at which execution is to be stopped and control of the processor switched to the debugger. Mechanisms for creating and removing breakpoints are provided by most debugging tools.

CISC (Complex Instruction Set Computer: Describes the architecture of a processor family. CISC processors generally feature variable-length instructions and multiple addressing formats and have a small number of general-purpose registers.

C: A popular high-level programming language that is the standard for many microcontrollers.

Capacitor: Component which stores electrical energy. Capacitance is measured in farads.

DRAM (dee ram) Short for Dynamic Random Access Memory.: A type of RAM that maintains its content only as long as the data stored in the device is refreshed at regular intervals. The repetitive row by column refresh access cycles are usually performed by a peripheral called a DRAM controller. If this isn't done every few milliseconds, some or all of the data stored in the memory can be lost.

embedded system: n. A combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a dedicated function. In some cases, embedded systems are part of a larger system or product, such as a stoplight on the corner that is also connected to a master traffic control system that can synchronize a number of traffic lights in one area.
EXAMPLE: Microwave ovens, cell phones, calculators, digital watches, VCRs, cruise missiles, GPS receivers, heart monitors, laser printers, radar guns, engine controllers, digital cameras, traffic lights, remote controls, bread machines, fax machines, pagers, cash registers, treadmills, gas pumps, credit/debit card readers, thermostats, pacemakers, blood gas monitors, grain analyzers, and a gazillion others.

EPROM: (ee-prom) abbr. A type of ROM that can be erased by exposing it to ultraviolet light. Once erased, an EPROM can be reprogrammed with a device programmer. Short for Erasable Programmable Read Only Memory. A window in the device allows ultraviolet radiation to enter the device and reset the ROM circuitry to its initial state.

glitch: n. An unwanted, spurious logic pulse of very short duration. Any unwanted, erratic, and generally nonreproducible behavior of a system is termed a glitch. Most result from poor timing or bad combinatorial design.

I/O pin: External microcontroller's connector pin which can be configured as input or output. In most cases the I/O pin enables a microcontroller to communicate, control or read information.

memory-mapped I/O: n. A common hardware design methodology in which peripheral control and status registers are mapped into the memory space rather than the I/O space. From the software developer's point of view, memory-mapped I/O devices look very much like memory devices. Their registers can even be accessed via ordinary pointers and data structures, greatly simplifying device driver implementation.

Microcontroller: A highly integrated microprocessor designed specifically for use in embedded systems. Microcontrollers typically include an integrated CPU, memory (a small amount of RAM, ROM, or both), and other peripherals on the same chip. Common examples are Microchip's PIC, the 8051, Intel's 80196, and Motorola's 68HC11 and 68HC12 series.

object code: n. A set of processor-readable opcodes and data. The output of compilers and assemblers and the input and output of a linker are files containing object code. However, there are a variety of standardized and proprietary object file formats, meaning that development tools from one vendor can only rarely read the object code produced by those of another.

ZIF socket: (ryymes with stiff) n. An IC socket that is designed for ease of chip insertion and removal. Short for Zero Insertion Force.

Glossaryof Computer Programmingand Robotics Terms