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ARO
After Receipt of Order.
Access
time
Time interval between the instant that
a piece of information is requested
from a memory device and the instant
the information is supplied by the memory
device.
Array
The area of the RAM that stores the
bits. The array consists of rows and
columns, with a cell at each intersection
that can store a bit. The large rectangular
section in the center of the die where
the memory is stored. |
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BGA
Ball Grid Array.
Bandwidth
The amount of data that can be moved
through a particular interface in a
given period of time, e.g. a 64-bit
wide, 100 MHz SDRAM data bus has a bandwidth
of 800 Megabytes per second.
Bare
board
A printed circuit board (PCB) that does
not have any components on it.
Block
diagram
A circuit or system drawing concerned
with major functions and interconnections
between functions.
Burn-in
The process of exercising an integrated
circuit at elevated voltage and temperature.
This process accelerates failure normally
seen as "infant mortality" in a chip.
(Those chips that would fail early during
actual usage will fail during burn-in.
Those that pass have a life expectancy
much greater than that required for
normal usage.)
Bus
An electronic traffic lane through which
electrical signals are carried through
one chip to another chip. For example,
the address bus between an SDRAM and
a DRAM controller takes the electrical
signals which define a certain address
and transfers them to the SDRAM memory. |
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CAS
Column-address-strobe. The signal which
tells the DRAM to accept the given address
as a column-address. Used with RAS and
a row-address to select a bit within
the DRAM.
CAS-B4-RAS
Column Address Strobe Before Row Address
Strobe. A fast refresh technique in
which the DRAM keeps track of the next
row it needs to refresh, thus simplifying
what a system would have to do to refresh
the part.
CMOS
Complementary Metal Oxide Semiconductor.
A process that uses both N- and P-channel
devices in a complimentary fashion to
achieve small geometries and low power
consumption.
Clock
rate
The number of pulses emitted from a
computer's clock in one second; it determines
the rate at which logical or arithmetic
gating is performed in a synchronous
computer.
Column
Part of the memory array. A bit can
be stored where a column and a row intersect.
Controller
One of the major units in a computer
that interprets and carries out the
instructions in a program.
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DIP
Dual In-line Package.
DRAM
Dynamic Random Access Memory. A type
of memory component used to store information
in a computer system. 'Dynamic' means
the DRAMs need a constant 'refresh'
(pulse of current through all of the
memory cells) to keep the stored information.
(See also RAM and SRAM.)
Date
code
On boards: The date of preliminary release
(the date that a printed circuit boards
are approved for fabrication.) On component:
The date of manufacture. In Test area:
The code (on the part) showing the year
and work week the part was marked.
Die
An individual rectangular pattern on
a wafer that contains circuitry to perform
a specific function. The internal circuitry
is made of thousands of tiny electronic
parts. 'Die' refers to a semiconductor
component or part that has not yet been
packaged (also known as 'IC' (Integrated
Circuit) or 'chip').
Die
size
The physical measurements of the die.
Direct
memory access
A computer feature that allows peripheral
systems to access the memory for both
read and write operations without affecting
the state of the computer's central
processor.
Dry
pack
The process of preparing product for
shipment in moisture vapor barrier bags.
This process includes tubed or reeled
product and a clay desiccant, and an
HIC(Humidity Indicator Card), vacuum-sealed
in a moisture vapor barrier bag.
Dynamic
Type of RAM (Random Access Memory).
To keep data in the D(ynamic)RAM memory,
this data needs to be 'refreshed' (recharged).
The electric charge fades out of a DRAM
like air seeps out of a balloon. Because
of this change, it is called 'Dynamic.'
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E2PROM
Electrically Erasable PROM.
EEPLD
Electrically Erasable Programmable Logic
Device. A CMOS PLD made by using EEPROM
technology. It can be erased and reprogrammed.
EEPROM
Electrically Erasable, PROgrammable,
read-only Memory chip. EEPROMs differ
from DRAMs in that the memory stays
in even if electrical power is lost.
Also, the memory can be erased and reprogrammed.
EPROM
Erasable PROM.
ESD
Electrostatic discharge. The dissipation
of electricity. ESD can easily destroy
the semiconductor product.
Encapsulation
The process of applying a cured-plastic
protective housing to components. A
mold compound. An Assembly step.
Etch
A process using a chemical bath (wet
etch) or a plasma (dry etch) that removes
unwanted substances from the wafer surface.
Ethernet
A local area network allowing several
computers to transfer data on a communications
cable.
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Failure
rate
Description of the rate at which parts
fail, usually expressed as percent per
1,000,000
Fall
out
Material that fails various tests within
the component manufacturing process.
Flash
memory
Flash memory is a non-volatile memory
device that retains its data when the
power is removed. The device is similar
to EPROM with the exception that it
can be electrically erased, whereas
an EPROM must be exposed to ultra-violet
light to erase.
Flat
panel display
The computer and display used at each
die attach machine to display the map
and/or messages pertaining to the map
or the lot.
Flatpack
A Teflon Polyurethane wafer holder used
to transport individual wafers. Flatpacks
can be stacked to carry and protect
several wafers at a time.
Flatpack
A flat, rectangular IC package type
with leads sticking out from the sides
of the package.
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GS
Indicates Goldstar as manufacturer (see
also LGS) |
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HIT
Indicates hitachi as manufacturer.
Heat sink
A structure, attached to or part of a
semiconductor device that serves the purpose
of dissipating heat to the surrounding
environment; usually metallic. Some packages
serve as heat sinks.
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IC
Integrated Circuit. A tiny complex of
electronic components and their connections
that is produced in or on a small slice
of material (as silicon).
IDT
Integrated Device Technology. |
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LGS
Indicates Lucky Goldstar as manufacturer.
Lead
The metal extensions from an IC package
or discrete component that connects
the component to the PCB. The leg or
contact point of the component that
is either physically soldered to a PC
board or placed within a socket for
connection.
Leadframe
A metal structure that is part of the
device. The die is attached to the leadframe.
Leads
Leads or Legs: The official name for
the metal 'feet' on an IC. Also called
'pins.' The part of the lead assembly
that is formed after a portion of the
lead frame is cut away. The part's connection
to the outside world.
Linear
circuit
A circuit that produces a voltage output
approximately proportional to the input
voltage, generally over a limited range
of voltage frequency.
Locator
pin
A pin in the mold which locates the
leadframe in the correct position on
the mold for processing.
Logic
circuit
An integrated circuit which provides
a fixed set of output signals according
to the signals present at the input.
Logic
gate
Several individual device functions
on an integrated circuit chip.
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MEG
Amount of memory equal to 1,048,576
bits of information. (Abbreviated Mb.)
MIPS
Millions of Instructions Per Second.
This measurement is generally used when
describing the speed of computer systems.
MIT
Indicates Mitsubishi as manufacturer.
MOS
Metal-Oxide-Semiconductor. Layers used
to create a semiconductor circuit. A
thin insulating layer of oxide is deposited
on the surface of the wafer. Then a
highly conductive layer of tungsten
silicide is placed over the top of the
oxide dielectric.
Megabit
One million binary pieces (bits) of
information.
Memory
configuration
The amount of memory in an IC and how
it is accessed. Also, a code on the
lot traveler used to indicate the IC's
memory configuration (e.g., 1M1 = 1
Meg x 1, 4M4 = 4 Meg x 4, etc.).
Memory
cycle
Minimum amount of time required for
a memory to complete a cycle such as
read, write, read/write, or read/modify/write.
Memory
types
Cache Data SRAM: quick-access chip.
DRAM 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.
Monolithic
Contained on one chip or substrate,
as a microprocessor system including
not only the logic but also memory or
input/output circuits.
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NMOS
N-channel Metal Oxide Semiconductor.
This pertains to MOS devices constructed
on a P-type substrate in which electrons
flow between N-type source and drain
contacts. NMOS devices are typically
two to three times faster than PMOS
devices.
NS
nanosecond (ns). One billionth of a
second; used to measure the speed of
the parts (e.g., -07 nanoseconds).
NVRAM
Non-Volatile Random Access Memory.
Nano
Literal: One-billionth (10 to the -9).
Diffusion: A tool used to measure the
thickness of a film on a wafer.
Nanometer
One billionth of a meter.
Nanosecond
One billionth of a second. Light travels
approximately 8 inches in 1 nanosecond.
Nonvolatile memory
A memory that retains information if
power is removed and then reapplied.
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Operating
system
Software controlling the overall operation
of a multipurpose computer system, including
such tasks as memory allocation, input
and output distribution, interrupt processing,
and job scheduling.
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PAL
Programmable Array Logic. A device that
can be programmed to do certain logic
functions. Then a fuse inside of the
device can be blown so the programmed
information can never be changed. Sometimes
called a PLD (Programmable Logic Device)
Language.
PCB
Printed Circuit Board; board upon which
there are layers of printed circuits
where DRAMs can be attached with solder
so that memory can be accessed.
PGA
Pin Grid Array.
PLA
Programmable Logic Array. An array of
logic elements that can be programmed
to perform a specific logic function.
It can be as simple as a gate or as
complex as a ROM and can be programmed
(often by mask programming) so that
a given input combination produces a
known output function.
PLD
Programmable Logic Devices. Devices
with 10-100 times higher level of integration
than a TTL; called programmable because
they can be customized in software rather
than in hardware.
PQFP
Plastic Quad Flat Pack. A square, flat
package with 18-52 gullwing leads located
around all four sides of the package.
Page
mode
Mode in which if RAS is kept low
and the DRAM is given a column-address
without being given a new row-address,
the chip will remember which row it
was on the last time and automatically
stay on that row. It is like saying
that all the bits along one row are
all on the same 'page,' and the part
will assume the same page is intended
until a different page is specified.
Part
number
The number used to identify the family,
capacity, and special characteristics
of the part (e.g., 4C4001: 4 = DRAM,
C = CMOS, 4001 = memory density (1 million
bits) and how it is accessed (4 access
lines).
Passive
device
A device incapable of current gain or
switching such as a resistor or capacitor.
Pin
The metal extensions from an IC package
or discrete component that connects
the component to the PCB.
Populated
board
A PCB with components.
Power
down
To turn the system's power OFF.
Power
up
To turn the system's power ON.
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Quad
flat pack
QFP: A flat, rectangular, integrated
circuit with its leads projecting from
all four sides of the package without
radius.
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RAS
Row-Address-Strobe: the signal that
tells the DRAM to accept the given address
as a row-address. Used with CAS and
a column-address to select a bit within
the DRAM.
RISC
Reduced Instruction Set Computing. The
design methodology is usually associated
with microprocessors. RISC chips use
simpler instructions, or commands, than
CISC chips. However, they need to use
more steps to perform many functions
that CISC chips perform in one step.
SPARC and MIPS chips are based on RISC.
RMA
Returned Material Authorization; required
if a customer desires to return products.
Also refers to parts that have been
returned from a customer.
Read
time
The amount of time required for the
output data to become valid once the
read and address inputs have been enabled;
generally called access time.
Row
Part of the RAM array; a bit can be
stored where a column and a row intersect.
Row
address
The number of the row where a particular
bit is stored.
Row/columns
Describes how many rows are on a wafer
map in the X direction. (X = left to
right. Y = top to bottom). |
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SDRAM
Synchronous Dynamic Random-Access Memory.
Delivers bursts of data at very high
speeds using a synchronous interface.
SGRAM
Synchronous Graphic Random-Access Memory.
SIMM
Single In-line Memory Module: a high-density
DRAM package alternative consisting
of several PLCCs connected to a single
printed circuit board. A small PCB designed
to mount in a socket on a larger PCB
providing a large memory upgrade in
a small space. One of the products of
Micron.
SIP
Single In line Package. A component
or module that has one row of leads
along one side. Many resistors come
in SIP form.
SOJ
Small Outline J-lead package. A rectangular
package with leads sticking out of the
side of the package. The leads are formed
in a J-bend profile, bending underneath
and towards the bottom of the package.
Lead counts range from 20 to 44 leads.
SRAM
(Static Random Access Memory) An integrated
circuit similar to a DRAM (Dynamic Random
Access Memory) with the exception that
the memory does not need to be refreshed.
Semiconductor
An element, such as silicon, that has
intermediate in electrical conductivity
between conductors and insulators, which
conduction takes place by means of holes
and electrons.
Shrink
A reduction in die (chip) size. A reduction
in the size of the circuit design resulting
in smaller die sizes that increases
the number of possible die per wafer.
Speed
The time it takes the RAM to put information
into its memory or get information out
of its memory. It is measured from the
time that an address and proper control
signals are given, until the information
is stored or placed in the device's
output(s).
Speed
grade
Our coding for the speed that the stored
information in the part can be retrieved
by a computer. For DRAMs, a -5 is 50
nanoseconds, a -6 is 60 nanoseconds,
a -7 is 70 nanoseconds, etc. For SRAMs,
a -10 is 10 nanoseconds, etc.
Static
RAM
Unlike volatile memory, static memory
retains its contents even when the main
current is turned off. The trickle of
electricity from a battery is enough
to refresh it.
Strobe
An input that allows parallel data to
be entered a synchronously.
Substrate
The actual structural material on which
semiconductor devices are fabricated,
whether passive or active. The term
applies to any supportive material,
such as the materials used in the fabrication
of printed circuits.
Surface-mount package
A J-leaded or Gullwing package (DJ,
TG, RG, G, EJ, etc.) that can be mounted
directly on the surface of P.C. Boards
(as opposed to through-hole packages).
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TI
Indicates Texas Instruments as manufacturer
TOSH
Indicates Toshiba as manufacturer.
TSOP
Thin Small Outline Package. It is thinner
and slightly smaller than an SOJ and
with gullwing-shaped leads. Our TSOP
is 1.2mm in height. Height distinguishes
the TSOP from the SSOP. A thin, rectangular
package with leads sticking out the
sides of the package. Lead counts range
from 20 to 40 leads.
Test
An electrical process every product
goes through which tests the parts for
parametric, speed, and functional failures.
Transistor
A semiconductor device that uses a stream
of charge carriers to produce active
electronic effects. |
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VRAM
Video Random-Access Memory.
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WD
Indicates Western Digital as manufacturer.
WE
Write-Enable; WE must be pulsed low
when data is written to the chip.
Write
time
Time expended from the moment data is
entered for storage to the time it is
actually stored.
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ZIP
Zig-zag In-line Package. |
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