Page 365 - Embedded Microprocessor Systems Real World Design

Debugger: See Monitor.
Device Driver: Software that provides an interface between the operating system and actual
hardware, such as video display boards or printers.
DMA (Direct Memory Access): A mechanism whereby a microprocessor temporarily gives up
its external bus to another processor (or other controller) and permits the other proces-
sor to directly access memory. Some microprocessors have built-in DMA controllers.
DRAM (Dynamic RAM): RAM that stores information as charge on a capacitor. It must be
periodically refreshed to renew the charge and retain data.
DSP (Digital Signal Processor): A microprocessor optimized for processing signals such as
sound, video, or radio frequency. A DSP typically includes hardware such as single-cycle
multiply hardware, barrel shifters, and other features that are designed to speed signal
processing.
Edge-Sensitive Interrupt: An interrupt that is recognized on a rising or falling edge.
EMC (Electromagnetic Compatibfity): A general term for the measure of a device or system
to operate in an environment with EMI. Usually used in relation to EMC testing or EMC
standards.
EMI (Electromagnetic Interference): A general term for interference caused by electro-
static discharge, radiated emissions, and magnetic interference.
EPROM (Erasable Programmable Read-only-Memory): A PROM that can be erased using
ultraviolet light.
ESD (Electrostatic Discharge): Static electricity that is discharged to, inside, or around
equipment.
Firmware: Software in machine-readable form, embedded in a ROM, PROM, EPROM, flash
memory, or other nonvolatile storage.
Flash Memory: A PROM that can be electrically erased and reprogrammed.
FPGA (Field Programmable Gate Array): A type of CPLD.
Harvard Architechue: A microprocessor architecture in which the code (instructions) is
in a separate memory area from the data. A given memory address typically references
different physical memory locations for code than for data.
HLL (High-Level Language): Any computer language that permits code to be developed
above assembler. C, Pascal, and BASIC are high-level languages.
ICE (In-Circuit Emulator): A device designed to plug into a circuit and replace the target
processor. A typical ICE permits the code to be run, breakpoints to be set, and the
registers and memory of the system to be examined.
Interrupt Controller: An integrated circuit or internal part of a microprocessor that
prioritizes interrupts and provides a vector to the processor.
IP (Internet Protocol): The protocol used for transmission of data over the Internet. IP
transmits a data packet from a source to a destination, and provides for breaking the data
into smaller blocks for transmission and reassembling them at the destination. IP is
normally used with TCP, the combination being called TCP/IP.

346 Glossary