Technical Terms Glossary

(AGP)-ACCELERATED GRAPHICS PORT
High speed graphics. Data shifts directly from the graphics controller and the computer memory, bypassing the cache in video memory.

ACCESS TIME
The average time period, for RAM, between a query for information and its completed access.

AMRAY
Equipment used to gauge crucial information from an area on a semiconductor component at various levels of operations through the use of a Scanning Electron Microscope(SEM).

ANSI-(AMERICAN NATIONAL STANDARDS INSTITUTE)
The United States organization responsible for setting information technology standards.

ARRAY
This is a large rectangular area in the center of a semiconductor component where memory is stored. Memory is stored in cells at each intersection of columns and rows, each of which holds a bit.

ASCII(American Standard Code for Information Interchange)
A method of encoding text as binary values. The ASCII system requires nearly 256 combinations of 8-bit binary numbers to support every possible keystroke from the keyboard.

ASIC-(APPLICATION-SPECIFIC INTEGRATED CIRCUIT)
These chips are created for a specific application rather than common use. Integrated-circuit chips are typically used in video boards and modems.

ASYNCHRONOUS
A process involving numerous tasks being performed independently in a system.

ATA-(AT ATTACHMENT)
A specification that integrates the drive control electronics interface. AT refers to the IBM PC/AT personal computer and its bus architecture.

AUTO PRECHARGE
A DRAM feature that enables the circuitry in a memory chip to automatically close a page at the end of a request from the processor for a single block of data.

BACKSIDE BUS(BSB)
BSB is the path in which data flows between the computer processing unit and the level 2 cache.

Bandwidth
The capacity to move data on an electronic line such as a bus or a channel. In short, the amount of data moved relative to a specific time frame. It is expressed in bits, bytes, or Hertz (cycles) per second.

Bank (logical memory bank)
A collection of memory slots in a computer which work together as a single unit. A bank cannot be partially filled and must be filled with like modules (same size, speed and type).

BANK SCHEMA
A procedure in which memory configuration is diagramed. Independent sockets are represented by rows and banks are illustrated by columns.

BASE RAMBUS
The beginning of Rambus technology, shipped first in 1995.

BEDO-(BURST EDO)
Similar to EDO DRAM, Burst EDO cycles are assembled in bursts of four. Bus speeds of Burst EDO range from 40mhz to FPM or EDO DRAM.

Binary
A method of encoding numbers as a series of bits. The binary number system, also referred to as base 2, uses combinations of only two digits- 1 and 0.

BIOS-(BASIC INPUT/OUTPUT SYSTEM
A set of low level RAMBUS that allow a computer's application programs and operating systems to read characters from the keyboard, output characters to printers, and interact with the hardware in other ways.

Bit
A binary digit- the smallest unit of information a computer system can process. It can have a value of only 1 or 0 (off or on). Single bits are too small to be of much use and are usually classified in groups such as bytes of binary words.

BLOCK
A block is a physical unit of data in a logical record that is expressed in bytes.

BLOCK DIAGRAM
A diagram of the system dealing with important functions and interconnections between them.

Brand-on-Brand Memory
(See original memory).

BUFFER
Shared information from devices operating at different speeds are held in the buffer. This buffer enables a device to function without delays from other mechanisms.

BUFFERED MEMORY
A module that houses buffers, which are used to help control the signals the memory chips receive. In addition, they allow the module to include more memory chips. Buffered and non-buffered memory cannot be combined.

BURN-IN
Using a high voltage and temperature to test an integrated circuit. This procedure will find those chips that tend to fail early during actual use. Chips that pass tend to have a longer life expectancy than required for regular use.

BURST EDO RAM
EDO Memory that processes four memory addresses in one burst. Speeds of the Bus may range from 50mhz to 66mhz.

BURST MODE
A high speed transmission of a series of addresses that occur when the processor asks for a single address.

Bus
The central communication avenue in a PCs system board. If normally consists of a set of parallel wires or signal traces that connect the CPU, the memory, all input/output devices, and peripherals.

Bus cycle
A single transaction between system memory and the CPU.

Byte
A unit of information made up of 8 bits. The byte is the key component of computer processing; most computer component specifications are measured in bytes or multiples thereof (such as kilobytes or megabytes).

Cache
A type of memory which is used to store frequently used instructions and data. Cache memories are used to increase the performance of computing systems by holding these frequently used instructions and data closer (in a speed-related context) to their final destination.

CAPACITANCE
The characteristic of a circuit element that enables it to store an electrical charge.

CAS LATENCY
The ratio between column access time and clock cycle time.

CAS-(COLUMN ADDRESS STROBE)
A memory chip signal that connects the column address of a specific location in a row-column configuration.

CE
The international symbol on all electrical equipment stating that it was certified per EN50082-2 (immunity) and EM5501A (emissions).

CHECK BITS
Additional data bits that a module supplies to support ECC.

CHIP-SCALE PACKAGE
Thin chip package in which electrical connections are usually through a ball grid array. Used in RDRAM and flash memory.

CHIPSET
The computer processing unit is supported by the chipset, a set of microchips which contain several controllers, determining how data travels between components and the processor.

CHMOS
Complementary High-density Metal Oxide Semiconductor.

CISC-(COMPLEX INSTRUCTION SET COMPUTING
A design logic in which chips combine multi-step instructions into one command. CISC is usually associated with microprocessors.

CLOCK RATE
The number of pulses discharged by a computer's clock in a one second interval. In a synchronous computer, clock rate establishes the time period in which logical or arithmetic gating occurs.

COB-(CHIP ON BOARD)
A technique or system in which semiconductor dice are connected to a PC board with bonded wires or solder balls.

COLUMN
A portion of the memory array whereby information is stored at the junction of a column and a row.

COMPACT FLASH
Removable storage cards that are efficient in terms of weight, size, and durability. In addition, they utilize small amounts of voltage and retain information when the power is off. Often used in digital cameras, printers, and handheld computers.

Composite Memory
A term used by Apple Computer to describe modules which use many low-density memory (4 Megabit) chips.

CONCURRENT RAMBUS
The second generation of Rambus technology.

CONTROLLER
A major component of a computer that interprets and performs program commands.

COPLANARITY
In terms of a semiconductor package, coplanarity refers to the condition of leads between two parallel planes.

CPU
Central Processing Unit. The "brains" of a computer system. A CPU is an integrated circuit which processes the bulk of the data and software instructions in a computer system. It is commonly referred to as "the processor" in a computer system.

CRC-(CYCLICAL REDUNDANCY CHECK)
A mathematical method to discover errors involving long runs of information with a greater degree of accuracy.

Credit Card Memory
A type of memory module (much like a PCMCIA card) named for its size. Credit card modules are commonly used in notebooks and other portable computing devices.

CRIMM-(CONTINUITY RIMM)
Direct Rambus memory in which the module does not contain any memory chips. Used to fill unused RIMM sockets to allow for an uninterrupted pathway for a signal.

DAMPING
The deterioration of oscillations as a result of the resistance in resonant circuits.

DATA OUT
The pathway that transmits the information from the RAM.

DATE CODE
A mark placed on PCBs and DRAM indicating the date that the product was manufactured.

DDR (Double Data Rate) or SDRAM II
The next generation of SDRAM. DDR is based on the same design as SDRAM, but its speed capabilities are enhanced. DDR allows data to be read on both the rising and the falling edge of the clock cycle, delivering twice the bandwidth of standard SDRAMs. DDR, in effect, doubles memory speed without increasing the clock frequency.

DIE
Die refers to one unpackaged part of thousands of tiny electronic parts forming the internal circuitry of a semiconductor component. It is also known as an integrated circuit or chip.

DIE PICK-UP TOOL
The tool on the machine that picks up the semiconductor component or part and places it on the leadframe.

DIE SIZE
Die size is the physical measurements of the die.

DIELECTRIC
Components used in semiconductor processing that, when voltage is applied, conduct no current. Examples of dielectrics include silicon dioxide and silicon nitride.

DIELECTRIC DEPOSITION
When a layer of deposited oxide is applied to separate (isolate) two metals in a double-level metal process. Must be accomplished in a way that prevents hillock formation on the top level.

DIMM
Dual In-Line Memory Module. A type of memory with contacts along one edge of a printed circuit board. A DIMM is much like a SIMM except the contacts on either side of a DIMM are not electrically connected like they are on a SIMM (pin 1 on the back and pin 1 on the front do not make the same connection). See also: memory module, SIMM.

DIP (Dual In-line Package)
A form of DRAM component packaging. DIPS are installed either in sockets or permanently soldered into a hole extending into the surface of the printed circuit board.

DIRECT ADDRESS
A memory address contained as part of the instruction.

DIRECT MEMORY ACCESS
A computer characteristic that enables peripheral systems to access memory for read and write operations, yet not affect the central processor of a computer.

DIRECT RAMBUS
Rambus technology's third generation, which offers a completely new DRAM architecture for high-performance PCs.

DISTRIBUTED PROCESSING
A process which frees the CPU of the details of block transfers by utilizing intelligent input/output controllers and direct memory access.

DRAM
Dynamic Random Access Memory. The most common form of primary storage used in computer systems. This type of memory must be 'refreshed' periodically to maintain the stored data (hence the term dynamic). The data in DRAM is lost when the power is removed from the circuit: therefore, the data in DRAM must be moved to a secondary storage device such as a hard drive floppy drive.

DRIVER BOARD
A PCB that transmits signals between the interface board of the oven and the DUT board. For each oven slot, there is a corresponding driver board situated in the rear of the oven.

DRY PACK
A method for preparing product to be shipped. It involves placing product, a clay desiccant, and an HIC (humidity indicator card) into a vacuum-sealed moisture vapor barrier bag.

DUAL INDEPENDENT BUS
Intel-developed technology that can access the processor through a front and backside bus. This allows for an expanded bandwidth.

DUAL-BANKED
A memory module having two banks.

DUT-(DEVICE UNDER TEST)
Device under test, or also known as UUT (unit under test).

DYNAMIC
A form of RAM that requires data to be refreshed due to a change in the memory's electric charge, caused by the diminishing of the charge in the memory.

EAROM
Electrically Alterable Read-Only Memory

ECC memory
Error Correction Code memory. An advanced form of parity memory which is used in some server-class computers. ECC memory can detect multiple bit errors (which halt the system or notifies the user before crashing) and can also correct single bit errors without stalling the computer.

EDO
A DRAM design that allows for quicker access to memory as compared to Fast Page memory.

EDO DRAM
Extended Data Output DRAM. EDO RAM is a new DRAM technology which is faster than industry-standard fast page mode DRAM. EDO memory devices shorten the read cycle between memory and the CPU which can result in about a 10% increase in memory access speed over standard fast-page mode DRAM.

ENCAPSULATION
The procedure in which protective cured-plastic is applied to components.

EOB
End of Buffer

EOS (ECC on SIMM)
A data-integrity checking technology that features ECC data-integrity checking built onto a SIMM.

EPROM-ERASABLE PROGRAMMABLE READ-ONLY MEMORY
Erasable, programmable, read only memory chips generally consisting of UV permeable quartz windows.

ESD-ELECTROSTATIC DISCHARGE
A discharge of electricity that is harmful to computer memory components.

ESDRAM-ENHANCED SYNCHRONOUS DRAM
More efficient than SDRAM in terms of speed, power consumption and cost.

ETHERNET
A high speed network that links users together and provides file sharing and communication capabilities.

EVEN PARITY
A type of data integrity checking where the parity bit checks for an even number of 1's.

FAILURE RATE
The rate at which components fail, usually expressed as percent per 1,000,000.

FALL OUT
Failed material from the component manufacturing process.

FAST-PAGE MODE
A common form of DRAM. data access technology. DRAM is accessed by dividing the memory into pages. To find stored information, the computer finds the proper page first and then looks for the information it needs. Fast-page mode DRAM allows the computer to obtain data in half of the time as long as the data being sought is on the same page as previous data.

FAT-FILE ALLOCATION TABLE
Organizational system used by DOS for files stored on hard, floppy, and other disk media.

FBGA
A ball grid array package consisting of a fine pitch ball set up located on the package's underside.

FIT
Failure in time.

FLAG
A status bit that indicates the condition of the processing unit.

FLASH MEMORY
See compact flash.

FLIPFLOP
Two stable states of a circuit that can be interchanged. They are the storage components in most SRAMs.

FORM FACTOR
The physical qualities used to describe computer memory hardware. Examples include size and configuration.

FPU- Floating Point Unit
An integrated circuit which is specifically designed for processing floating point numbers. An FPU is used to supplement the processing capabilities of a CPU and is commonly required for CAD and other graphics-intensive applications. An FPU is also referred to as a math co-processor.

FREQUENCY CONVERTER
A device that can transfer the frequency of an alternating current, regardless of the voltage or phase changes.

FRONTSIDE BUS
Frontside Bus is the data pathway that runs between a computers CPU and main memory.

FTP- FILE TRANSFER PROTOCOL
A set of guidelines that enable computers to communicate with each other during file transfers. These rules are used when downloading files to your computer from another computer across the internet.

Gigabit
Approximately 1 billion bits: 1 bit x 1,024(3) (that is, 1, 073,741,824 bits).

Gigabyte
A Gigabyte is composed of 1024 Megabytes or 1,073,741,824 bytes (1024^3 bytes). The term Gigabyte is used frequently to describe large forms of storage such as tape storage or hard drives.

GND
Ground

Gold lead module
A memory module which has gold-plating on its connector edge contacts. Some users and manufactures have a preference with regard to the metal coating used on the contacts of memory modules.

Hard drive
A secondary memory device used to store information in a computer system even when the power is removed from the system. A hard drive is a device with at least one enclosed platter (like a record but on a smaller scale) and a needle-type head which reads and writes data to the platter. Hard drive sizes are usually specified in Megabytes or Gigabytes and are available in internal and external models.

HARD FAILURE
A semiconductor component that fails functionality testing. 99% of the time these defects are visible, such as poly or metal bridging, missing geometries or layers, particles, or contaminates.

HEAT SINK
A component usually required by CPUs to disperse heat to the surrounding environment.

HEAT SPREADER
Typically an aluminum sheath that covers an electronic mechanism to dissipate heat.

HPFS(HIGH PERFORMANCE FILE SYSTEM
A file system that offers enhanced performance compared to the FAT file system. HPFS supports long file names, in addition to handling hard disks of any size with significant decrease in waste.

HPM
Hyper Page Mode also known as EDO.

HTOL
High Temperature Operating Life

I/O INPUT/OUTPUT
A generic term used to describe an action for which information on a computer is sent and received.

I/O PORT
A connection to the CPU for the purpose of providing an informational pathway between the CPU and its external devices, such as a keyboard. It can be an input port or an output port, or even a bi-directional port.

IC (Integrated Circuit)
An electronic circuit on a semiconductor chip that consists of both components and connectors. This circuit is usually packaged in a plastic or ceramic case with external connector pins.

ID(IDENTIFICATION DETECT)
Pins that are present on DIMMs, that provide data to the system using the module.

INTELLIGENT
Electrical functioning of parts are continuously or periodically monitored and recorded under various voltages, temperatures, and refresh conditions during burn-in processes. This monitoring allows intelligent decisions to be made about integrated circuits.

INTERLEAVING
Procedure to increase speed of memory. An example would be using separate memory banks for odd and even addresses, enabling the next byte of memory to be accessed while the current byte is refreshing.

IO CARD
A printed circuit board that communicates between a computer and an interface board.

IRQ(INTERRUPT REQUEST)
An indication to the CPU from a hardware device, such as a keyboard, signifying that it needs attention. These signals are transported along IRQ lines, and are prioritized by the interrupt controller which then delivers them to the CPU.

ISA (INDUSTRY STANDARD ARCHITECTURE)
A bus design of the IBM PC/AT and the PC compatible computer systems in use today.

ISD
A polysilicon used as an underlying layer of the HSG poly for the purpose of increasing conductivity.

ISO
International Standards Organization.

JEDEC (Joint Electronic Devices Engineering Council)
An international body of individuals that create Semiconductor engineering standards such as the guidelines for memory operations, features, and packaging.

KEYS
Notches that prevent memory from being installed incorrectly or into the wrong system.

Kilobit
Approximately one thousand bits: 1 bit x 2(10) (that is, 1,024 bits).

Kilobyte
Approximately one thousand bytes: 1 byte x 2(10) (that is, 1,024 bytes).

LEAD
Metal extensions that connect an integrated circuit component to a PC board. These extensions are either physically soldered or placed into a socket for connection.

LEADFRAME
A metal framework in which the die is attached to.

LEADS
The official term for the metal pins on an integrated circuit. The portion of the lead assembly that is created after a section of the leadframe is cut away. See lead.

LEVEL-1 CACHE
A level-1 cache memory which is usually located inside the CPU and works very closely with the CPU registers and processing units. These caches are usually small compared to level-2 cache memories (around 1k to 32k). A level-1 cache aids the CPU’s efficiency and speed by storing frequently used instructions and data.

LEVEL-2 CACHE
A level-2 cache memory that is external to the CPU and caches data and instructions which are transferred between the CPU and RAM. These caches can be in the form of memory chips soldered to the system’s motherboard. Level-2 caches can range in size from 32k to over 1 Megabyte.

LIFE TESTING
A means to establish field reliability of electronic components through advanced testing.

LINEAR CIRCUIT
A circuit producing a voltage output proportional to an input voltage. Generally this occurs over a limited range of voltage frequency.

LINEAR REGULATOR
Power supply configuration in which voltage remains constant.

LINEAR SELECTION
The cheapest method of memory selection or input/output devices that dictates one address line per chip, resulting in overlapping.

LOCATOR PIN
A pin in the mold whose purpose is to locate the leadframe in the correct position during processing.

LOGIC BOARD
See motherboard.

LOGIC CIRCUIT
Based on the signals occurring at input a fixed set of output signals are provided by an integrated circuit.

LOGIC GATE
Consists of the functions of several individual mechanisms on an integrated circuit chip.

MCH-MEMORY CONTROLLER HUB
For motherboards using Intel's 820 and 840 chipsets, MCH is the interface between the processor, Accelerated Graphics Port and RDRAM.

MEGABIT
Amount of memory equal to 1,048,576 bytes of data.(abbreviated MB)

Megabyte
A megabyte is composed of 1024 kilobytes or 1,048,576 bytes. Megabyte is commonly abbreviated using ‘M’ or ‘Mb’. NOTE: In many cases, an megabyte is incorrectly stated as being 1 million bytes.

Megahertz
Commonly abbreviated as ‘MHz’. A unit of frequency that is equal to 1 million hertz (clock cycles per seconds). Computer processors are commonly specified by their type and clock speed which is expressed in Megahertz.

Memory
A term used for all types of electronic storage including RAM, hard drives, tape storage, CD-ROM, and floppies; however, the term memory is more commonly used to refer to a computer’s random access memory.

Memory Bank
A logical unit of memory in a computer, the size of which is determined by the computer's CPU. For example, a 32-bit CPU calls for memory banks that provide 32 bits of information at a time. One or more memory modules can make up a memory bank.

MEMORY BUS
The bus that travels between the CPU and the memory expansion slots.

MEMORY CONFIGURATION
The amount of memory in an integrated circuit and how that memory is accessed.

Memory Controller
The interface between system memory and the central processing unit. The memory controller consists of special circuitry- usually a microprocessor- within a computer system that interprets requests from the central processing unit in order to locate data locations, or addresses, in memory.

MEMORY CYCLE
The smallest amount of time required for memory to complete a cycle such as read or write.

Memory Module
A memory module is a printed circuit board with memory ICs soldered onto the surface. The circuit board has contacts or pin connectors which allow the module to be connected as a part of a memory bank in a computer system. Memory modules come in many styles, width (in bits), and depth (in words). See also: DIMM, SIMM.

MEMORY TYPES
Cache Data SRAM: quick-access chip DRAM dynamic random access memory SDRAM synchronous dynamic random access memory DDR SDRAM double data rate dynamic random access memory SLDRAM synchronous link dynamic random access memory RDRAM Rambus dynamic random access memory EPROM erasable, programmable, read only memory PROM Programmable, read-only memory RAM random access memory ROM read-only memory (permanent memory that cannot be changed SRAM static random access memory

MICRON
A unit of measure equivalent to one-millionth of a meter; synonymous with micrometer.

MIP MILLIONS OF INSTRUCTIONS PER SECOND
A method often used to characterize the speed of computer systems.

MNOS METAL NITRIDE OXIDE SEMICONDUCTOR
A technology, not to be confused with NMOS, that is used for EAROMs.

MOISTURE VAPOR BARRIER BAG
A vacuum-sealed bag whose purpose is to keep moisture out so that damage will not occur to the components inside.

MONOLITHIC
Housed on one chip or substrate, (i.e.. microprocessor systems including not only the logic but also memory or input/output circuits).

MOST
Metal Oxide Semiconductor Transistor

Motherboard
A computer’s main electronic printed circuit board. It typically contains the CPU, memory, and input/output circuitry. In many cases motherboards often have one or more expansion slots for adding capabilities to the computer at a later date. Also known as a logic, main, system, or for some, "the big green" board.

MTBF
Mean Time Between Failures.

MTH-MEMORY TRANSLATOR HUB
On motherboards using Intel's 820 chipset, MTH is the interface that enables SDRAM to be supported on a Direct Rambus Channel

MTTF
Mean Time To Failure.

MU MEMORY UNIT
Often a PCB covered with memory chips housing a specific amount of memory. Intel term for a type of card in a memory system card series.

NAND
A computer logic circuit that generates an output which is the reverse of an AND circuit.

NANO
One-billionth (10 to the-9). A tool used to measure the thickness of a film on a wafer.

NANOMETER
One-billionth of a meter.

Nanosecond (ns)
One billionth of a second. Memory data access times are measured in nanoseconds. For example, memory access times for typical 30- and 72-pin SIMM modules range from 60 to 100 nanoseconds.

NC
Not connected.

NEGATIVE CHARGE
Charges resulting from existence of electrons.

NIBBLE
Half of an 8-bit byte, or 4 bits.

NMOS- N-CHANNEL METAL OXIDE SEMICONDUCTOR
This refers to MOS devices built on a P-type substrate whereby electrons flow from the N-type source to the drain contacts. These devices are typically two to three times faster than PMOS devices.

Noncomposite
A term created by Apple Computer, Inc. that describes a memory module which uses 16-Mbit technology. For a given capacity, a noncomposite module will have fewer chips than a composite module.

Non-parity memory
Memory that does not incorporate extra memory chips or logic to help detect bit errors. Non-parity memory leaves error checking up to external circuits which the motherboard may possess.

NONVOLATILE MEMORY
Memory that does not lose data when power is removed and then reapplied.

NOR
Logical-Not-or

NTFS(NT FILE SYSTEM)
The native file system of Microsoft Windows NT, offering enhanced performance as compared to the FAT File System.

NVRAM
Non-volatile Random Access Memory

Odd Parity
A type of data integrity checking where the parity bit checks for an odd number of 1's.

OE-OUTPUT ENABLE
Referring to a component where data-in and data out are shared on the same pins, the OE needs to be triggered to request output data.

OHM
A unit of measure of electrical resistance.

OPEN
An interruption in a circuit causing an incomplete pathway in the current flow.

Original memory
Also called the brand-on-brand memory. A term used to describe memory modules which are built with a brand of chip mounted on a board of the same brand.

PAD
This conductive bonding island is strategically located on circuit chips allowing for inter-connecting circuit elements, or for bringing connections from circuit leads to the outside.

PAGE
The amount of bits which can accessed from a one row address.

PAGE MODE
A chip will remember what row it was on the last time and automatically stay on that row if the RAS is kept low and the DRAM is given a column-address without it being given a new row address.

PAL(PROGRAMMABLE ARRAY LOGIC)
A programmable device that can do certain logic functions, a fuse inside the device can then be blown so that the programmed data can never be changed.

Parity memory
Memory that contains extra chips or logic to help detect bit errors which can cause data corruption or system crashes. Simple parity checking memory can detect single bit errors and notify the user or halt the system. ECC parity memory can detect multiple bit errors and correct single bit errors.

PASSIVE DEVICE
A device, such as a resistor or capacitor, that is incapable of current gain.

PC100
Intel's PC 100 specification defines the requirements for SDRAM used on 100MHZ FSB motherboards.

PC133
The PC133 specification details the requirements for SDRAM used on 133mhz FSB motherboards. PC133 SDRAM can be used on 100mhz FSB motherboards but will not yield a performance advantage over PC100 memory at 100mhz.

PCB (Printed Circuit Board)
A component made up of layers of copper and fiberglass; the surface of a PCB features a pattern of copper lines, or "traces," that provide electrical connections for chips and other components that mount on the surface of the PCB.

PCI-PERIPHERAL COMPONENT INTERFACE
A local bus design that is often used in Pentium-based PCs. It offers a high-bandwidth data channel between system-board components.

PCMCIA
Personal Computer Memory Card Internal Association. A standard for memory cards, fax/modem cards, networking adapters, and other input/output devices. A PCMCIA card is about the size of a credit card and can conform to one of three standard sizes which specify final dimensions. Those standard sizes are Type I, Type II, and Type III.

PD(PRESENT DETECT)
Using the module, information is provided to the system by indicator pins on SIMMs and DIMMs.

PGA
Pin Grid Array.

PIF(PROGRAM INFORMATION FILE)
File used by Microsoft Windows 3.x to house configuration data regarding a DOS program.

PIN
Metal extensions from an integrated circuit package or component that connects it to the PCB.

PIN ONE HOLE
A hole located on the pin one side of the leadframe.

PIN ONE INDICATOR
Indentation or mark at the top of the part which indicates where the first lead of the die inside is found.

PIPELINE BURST CACHE
Cache that, by using pipelining and bursting functions, decreases the wait states and speeds memory access.

PIPELINING
A process whereby memory stores the requested memory contents into small cache composed of SRAM, it then immediately starts to fetch the next memory contents. This process results in a two-stage pipeline in which information is read from or written to SRAM in one stage and in the second stage it is read from or written to memory.

PLA (PROGRAMMABLE LOGIC ARRAY)
Programmed array of logic elements that can perform specific logic functions. Often mask programming is used so that a given input combination produces a known output function.

PLC-PRINTER CONTROL LANGUAGE
Defines a standard set of instructions for communicating with HP or HP-compatible printers. It is supported by almost every printer manufacturer.

PLD(PROGRAMMABLE LOGIC DEVICES)
Devices that contain 10-100 times higher levels of integration than that of a TTL. PLD is called programmable because it can be customized in software rather than in hardware.

PMOS(P-CHANNEL METAL OXIDE SEMICONDUCTOR)
MOS devices built on an N-type silicon substrate whereby holes flow between source and drain contacts.

POPULATED BOARD
A PCB with components.

PQFP(PLASTIC QUAD FLAT PACK)
Flat, square package that has gulling leads located around the four sides of the the package.

Proprietary memory
A memory card or module designed for a specific computer system which does not conform to an industry standard form factor.

PULL-UP
Method utilized to keep the output voltage of a device at a high level. This is often a resistor network that is connected to a positive supply voltage.

PWB(PRINTED WIRING BOARD)
A Board which has layers of printed circuits that DRAMs can be attached to with solder allowing memory to be accessed.

QFP-QUAD FLAT PACK
A rectangular integrated circuit that has leads projecting from all sides of the package without radius.

RAMBUS CHANNEL
An electrical procedure in which every product goes through to test for various failures.

RAMP
An extent of time in an oven when the temperature goes up.

RAM-Random Access Memory
A type of memory which can allow access to any cell in the memory as fast as any other cell by specifying that cells address.

RANDOM FAILURE REGION
A section of the bathtub curve that represents the useful portion of a device's life.

RANGE
In a block of information, range is the difference between the smallest and the largest values. Range is considered to be the simplest measurement of variation.

RAS
Memory chip signal that latches a row address of a specific location in a row/column matrix.

RDRAM
Rambus DRAM technology is a system-wide, chip-to-chip interface design that allows data to pass through a simplified bus. Rambus uses a unique RSL (Rambus Signaling Logic) technology.

READ RESTORE
Mode of operation utilized in core memory systems.

READ TIME
Is generally called access time, it is the amount of time needed for the output information to become valid once the read and address inputs are enabled.

READ/WRITE MEMORY
A term for Random Access Memories.

REFRESH
A process similar to recharging batteries, that maintains information stored in DRAM. Different DRAM components require various refresh methods.

Refresh rate
DRAM chips used on memory modules must be refreshed to retain their contents. Two common refresh rates are 2k refresh and 4k refresh.

Registered DIMMs
Registered DIMMs are essentially a specially buffered DIMM. Two special components are required to buffer the DIMM because of the tight tolerances of the PC-100 specification. The components are called a "register", and a PLL (Phase Locked Loop). All control and address signals are synchronized with the positive edge of externally supplied clocks and are registered on-DIMM and hence delayed by one clock cycle in arriving at the SDRAM devices. This pipelining allows the path between the memory controller and the DIMMs to be achieved in two clock cycles rather than one. Use of an on-board register also reduces the capacitive loading of the DIMM on input control and address signals.

RELATIVE ADDRESS
An area that indicates the position of memory location in a computer's routine, and it deals with base address rather than a memory location's actual address.

RELEASE TIME
Time information must remain stable after a circuit has been clocked, is also called hold time.

RESIST
Resist is also called photoresist, it is a material that prevents etching or plating to occur in the area it covers.

RIMM
Rambus Inline Memory Modules used for RAMBUS DRAM.

RIMM CONNECTOR
A Direct Rambus memory socket.

RISC-REDUCED INSTRUCTION SET COMPUTING
Usually associated with microprocessors, these chips use simple instructions , and commands. RISC chips use more steps to perform several functions that CISC chips can perform in one step.

RISE TIME
Time required for a signal level change to increase 10% to 90% of its final specified value.

ROM-READ ONLY MEMORY
A generic term for the non-volatile memory which can be read from but not written to. ROM usually contains a computer's BIOS. SEE also BIOS, EPROM, and EEPROM.

ROW
A row is part of the RAM array. At the intersection of a row and column a bit can be stored.

ROW/COLUMN
Describes the amount of rows are on a wafer map in the X direction. (X=left to right, Y=top to bottom)

RPL
Acronym used to represent RS/1 Programming Language. RPLs are procedures written in RS/1's built in programming language and they are utilized to automate tasks and analyses.

RW
Read/Write memory.

SCRIBE
A mark on the wafer that identifies it and the lot that it came from. This scribe marking is located on the front of a wafer, opposite the major flat.

SDRAM
Synchronous DRAM. A type of DRAM that is synchronized to the computer’s system clock. Because the CPU and memory are running ‘in sync’, data transfer speed is increased. Synchronous DRAM is not in widespread use because of its high cost when compared to other forms of DRAM.

Self refresh
A type of memory technology which refreshes on it’s own and does not require a refresh signal like a standard DRAM. Self refresh DRAM chips are used for notebook computers because of their reduced power consumption and minimal need for external support circuitry.

SEMI CONDUCTOR
Element, such as silicon, in which conduction occurs by means of holes and electrons.

SER-SOFT ERROR RATE
Errors that are caused by a temporary disruption of memory cells.

SGRAM-Synchronous Graphics Random Access Memory
High speed VRAM which contains a graphic-specific read/write feature. Data is allowed to be changed, after it is recovered, in blocks instead of as a single entity. This lowers the amount of read and writes that must be preformed by the memory. The efficiency of the graphics controller is also enhanced.

SIMM - Single In-Line Memory
A memory module that plugs into a computer’s RAM expansion socket. The front and back contacts on a SIMM are connected electronically.

SIMM SOCKET
A motherboard component which holds a single SIMM.

SIM-SINGLE IN-LINE MODULE
Same as Single In-Line Package except it has a connector edge instead of leads.

SINGLE -BANKED
A module containing only one bank or row.

SIP-SINGLE IN-LINE PACKAGE
A component or module that consists of a row of leads along one side. Many resistors come in the form of Single In-Line Packages.

SLDRAM
SLDRAM was once a main memory technology developed by a group of twelve manufacturers of DRAM as an alternative to Direct Rambus technology.

SLIP-SERIAL LINE INTERNET PROTOCOL
A protocol for connecting a computer to the Internet using a dial-in connection. In addition, it is used to run TCP/IP over phone lines. See also PPP and TCP/IP.

SMART CARD
An electronic device, about the size of a credit card. It can store information and programs, and at the same time, enhance security.

SO DIMM (Small Outline Dual In-line Memory Module)
An enhanced version of a standard DIMM, SO DIMMs are small and thin. The small outline DIMM is about half the length of a typical 72-pin SIMM. This form of memory is typically used in laptops.

SOFT ERROR
A temporary disruption of a memory cell that causes an error.

SOFT ERROR FAIL
During a soft error test a part has temporary, single-bit failure.

SOJ- Small Outline J-lead
A chip package commonly used for surface mounting applications. An SOJ chip is usually rectangular - shaped with J-style leads along the two long sides of the chip package.

SPC-STATISTICAL PROCESS CONTROL
Utilization of statistics to determine uniformity around target values.

SPD-SERIAL PRESENCE DETECT
Enhanced Presence Detect that uses EEPROM to store module timings, configurations, and data from the manufacturer.

SPEED
The amount of time RAM takes to put data into its memory or vice versa. Speed is measured from the time an address, and control signals are given, until all information is stored in the device's outputs.

SPEED GRADE
A code for the speed that stored data in a part can be retrieved by the computer.

SPHS
Spin high speed operation found in coat and develop programs.

SPIKE
Is the measure of variation for particular processes or product characteristics. A spike is the sudden severe portion of the pulse that considerably exceeds its normal amplitude.

SRA
Standard Readability Assessment.

SRAM - Static Random Access Memory
A type of memory which does not have to be periodically refreshed like DRAM; however, the contents of SRAM are lost (like DRAM) when the power is removed. Static RAM is typically used for cache memory because it is several times faster than standard DRAM. SRAM is much more expensive than DRAM so it is not used for large memories.

STARTING ADDRESS
Is the smallest or lowest address that memory systems respond to.

STATIC RAM
Memory chip requiring power to retain its content. Ordinarily used for cache memory, SRAM is faster but more expensive and bulky as compared to DRAM.

Storage
A medium designed to hold data, such as a hard disk or CD-ROM.

STROBE
Inputs that allow parallel information to be entered asynchronously.

SUBSTRATE
A structural material on which a semiconductor device is fabricated, it may be passive or active. Substrate applies to supportive material, like those used in the fabrication of printed circuits.

SURFACE-MOUNT PACKAGES
As opposed to through-hole packages, surface-mount packages, such as J-lead, Gullwing package, or BGA, that can be mounted directly to the surface of a PCB.

SWAPPING
Refers to the utilization of the hard drive as memory when RAM is full. SEE also virtual memory.

SWITCHES MENU
User-configurable options for a printed circuit hardware configuration that is contained in a menu in BIOS.

SYSTEM BOARD
SEE motherboard.

TAG
A memory index for data stored in L2 cache.

TBD-TO BE DETERMINED
Term used on quotes in reference to shipping dates.

TCAC
The time it takes to get a bit of data out of a part after CAS comes down. TCAC is a measurement of how fast the part is.

TCE-THERMAL COEFFICIENT OF EXPANSION
Constant that depicts changes in the linear dimensions, with respect to the temperature of a device of the material.

TEST
An electrical procedure in which every product goes through to test for various failures.

TG
A package type code for TSOP.

Third party memory
Third party memory refers to name brand chips mounted on printed circuit boards manufactured by a different company. This is not necessarily different form original memory modules when quality components are used.

Tin lead module
A memory module which uses tin and lead solder for a coating on its connector edge. Some users and manufacturers have a preference with regard to the metal coating used on the contacts of memory modules.

TRANSISTOR
Active electronic effects are produced by this semiconductor device that utilizes a stream of charge carriers.

TRANSMISSION LINE TECHNOLOGY
Technology supporting the backside bus in Direct Rambus Systems. This process involves information being pipelined in simultaneous packets, whereby the memory controller combines the packets for frontside bus transfer and communication to the processor.

TRS-TERMINATE, STAY-RESIDENT
A name commonly applied to a DOS program that terminates and remains resident in memory allowing operation in the background while other programs run in the foreground.

TSOP - Thin Small Outline Package
A chip package with leads that extend out and lay flat. The package is usually rectangular-shaped with leads along the two long sides of the chip package. The unique feature of the TSOP package is its height when mounted on a board. TSOP is only about one-third (or less) the height of a standard SOP chip.

UM
Micron (or Micrometer). A unit of length that is equal to one millionth of a meter.

UMB-UPPER MEMORY BLOCK
A block of memory (between 640k and 1MB) useful for loading TSRs and device drivers so that they do not take up the limited memory that is below 640k, that is generated in upper memory by a 386 memory manager.

UNBUFFERED MEMORY
Memory that does not contain buffers or registers on the module itself, but rather, these devices are found on the motherboard.

URL-UNIFORM RESOURCE LOCATOR
A logical address that locates a resource on the Internet.

US
Microsecond, one millionth of a second.

VARIABLE
The condition, transaction, or event that changes or may change as an effect of processing additional information throughout a system.

VCC
Collector Common Voltage

VCM-VIRTUAL CHANNEL MEMORY
Memory technology proposed by NEC which allows various blocks of memory, each containing its own buffer, to communicate with the controller separately. This improves the efficiency of operations by designating system tasks their own virtual channel.

VESA-VIDEO ELECTRONICS STANDARDS ASSOCIATION
A group of computer manufacturers responsible for the SVGA video standard and the VL-BUS. SEE also SVGA and VLB.

VFAT-VIRTUAL FILE ALLOCATION TABLE
A 32bit file extension of the FAT file system used by Windows 95 to handle data stored on disks. It supports long filenames while still compatible with FAT volumes.

VIRTUAL MEMORY
Simulated memory. Data is swapped to the hard disk when RAM is full, and then back to the RAM as necessary. SEE swapping.

VL-BUS-VESA LOCAL BUS
A 32bit local bus running between the CPU and peripheral mechanisms at speeds up to 40mhz.

VRAM- Video Random Access Memory
The type of memory in a display adapter used to create image that appears on a video screen.

VSS
This is the abbreviation for a ground connection, i.e.. A ground wire on a battery.

WAIT STATE
An idle period for the processor, caused by the different clock speeds of the processor and of memory.

WE (WRITE ENABLE)
When information is written to a chip the write enable must be pulsed low.

WRAM-WINDOW RANDOM ACCESS MEMORY
Samsung Electronics' dual ported memory. It is usually on a video or graphics card, and though it has a 25% higher bandwidth than VRAM, it is cheaper.

WRITE TIME
The amount of time expended from the moment data is entered for storage to the actual time it is stored.

XMS-EXTENDED MEMORY SPECIFICATION
A memory allocation scheme allowing programs to use memory above 1MB without interference with each other. Access to XMS memory is made easier by an XMS driver.