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L
- L cell
- See logic cell.
- LLCC
- Abbreviation for leadless chip carrier. Package type.
- LDCC
- Abbreviation for leaded chip carrier. Package type.
- Leaded chip carrier
- See LDCC.
- Leadless chip carrier
- See LLCC.
- LED
- Light-emitting diode.
- Load delays
- The amount of time delay caused by loading on the macro due to electrical
effects of fan-out loading, wire-OR loading, and the physical metal
etch. For output macros, the time delay caused by the system and package
pin capacitive loads.
- Logic array
- An array of predefined base-wafer transistor, diode and resistor components
that can be configured into a variety of logical circuits by way of
n-levels of metal interconnect. Levels number two or three for semi-custom
arrays contain the logic.
- Logic cell Internal cell, Function cell
- Cells designed for logical functions and not for I/O; can accommodate
certain buffers.
- Logic functions
- See functionality, includes AND, OR, NOT, NAND, NOR, INVERT and combinations
of these.
- Low-power macro
- A macro option designed to use less power than the standard option
at the cost of slower propagation delays.
- Low-power option
- Same as low-power macro; macro options.
- LSI
- Large Scale Integration, from 200 to 1000+ equivalent gates on a chip.
- LSTTL
- Low power Schottky TTL.
M
- Macro
- Pre-designed logical function with a name; May be multiple cells.
- Macro functions
- Logic functions that are performed by the macros in a library.
- Macro library
- The collected set of macros that are valid for use in a given array
or array series.
- Macro library element
- A macro, either simple (0.5 cell to n cells) or complex.
- MacroMatrix
- An integrated set of software tools for logic array design.
- Macro options
- Variations on the basis macro specification such as low-power, high-power,
high-speed, termination or pull-down, pull-up resistors, etc. The propagation
time and current specifications of the options will vary from the standard
while the function performed does not. Drivers do not usually have options.
Different ECL types and power supply configurations are handled by macro
versions.
- Macro oriented
- An array arranged as repeated groups of configurable components in
contrast to a "sea of primitive gates" structure.
- Macro version
- A macro meant for another ECL type (ECL 10K versus ECL 100K) or power
supply (+5V REF ECL versus STD REF ECL). The parameters are identical.
- Mask
- A level of interconnect or via (through-holes) defining one layer
of a die.
- Mask-programmable devices
- Example devices are gate arrays and ROMs.
- Monostable
- A circuit with one stable state and one quasi-stable state. Also called
a one-shot, a delay circuit, a single-cycle circuit, a gating circuit.
- MOS
- Metal-oxide semiconductor Developed for denser, lower performance
circuits. Simpler processing and fewer mask layers allow larger circuits
to be produced.
- MSI
- Medium Scale Integration. 20-100+ equivalent gates on a chip.
- MSI functions
- Functions of size/complexity appropriate to MSI devices; Medium scale
functions; MUX, decoder, register. See above.
- MSI library
- A collection of large, multiple cell macros
- MSI logic macros
- Large, multiple cell macros
- MUX
- Multiplexor, also spelled multiplexer A select one of n device where
n input lines are reduced to one output, the nth line active is selected
by one or more selection control inputs.
N
- Net
- The etch required to connect one output pin to all of its destination
pins plus any etch required to connect any other sources wire-ORed to
that pin. Also described as "photolitho-graphically determined inter-connect
metalization". A wire-net refers to the representation of a net on a
circuit schematic. A net segment is a piece of a net from one end to
a node.
- Netlist
- A listing of all the interconnects within a circuit.
- Node
- The interconnect point of two or more nets.
- ns
- Nanosecond, 10-9 sec.
O
- Output cell
- A cell that accommodates output-only functions.
- Output macro
- Macro that performs the translation from internal levels to external
levels for a device. Depending on the cell complexity, it may require
the use of a buffer or may provide its own.
- Output.dly
- A data file created and used by AMCCANN.
- Overhead circuitry
- Overhead circuitry consisting of bias generators and voltage references
is pre-defined in the base array.
- Overhead current
- The current dissipated by the overhead circuitry. It may be a function
of the numbers and types of interface macros used.
- Oxide-isolated
- Another bipolar technology.
P
- Package
- The enclosure used to protect the die and interconnect it to the
board.
- Package power and ground planes
- Newer packages provide internal planes to which fixed power and ground
pads may be connected. Allow the 1 to 1 ratio of fixed power and ground
pads to package power and ground pins to be altered. Allow added power
and grounds to connect to internal planes only if placed on pads accessible
to the internal planes.
- Package signal pin
- An external package pin that carries a variable signal level as opposed
to one that carries power or ground.
- PAL
- A registered Trademark of Monolithic Memories, Inc. Program-mable
Array Logic. An optimized variant of a PLA (more inputs, more outputs,
or more functionality by reducing the width of the OR portion of the
array). "AND" array user-programmable, "OR" array pre-programmed, groups
of product terms are ORed to the y outputs according to the pre-arranged,
pre-programmed pattern.
- Passive components
- Example passive components of a die are resistors, capacitors and
conductors.
- PC or PCB
- A printed circuit board has interconnections between points printed
in metal on the board. "PC board" could be confused with a personnel
computer board.
- PGA
- Pin grid array; A package type suitable for high pin-count requirements,
it has pins .100 inch apart on 10x10 through 17x17 matrices brazed perpendicular
to the die cavity.
- PLA
- Programmable Logic Array Either AND-OR or NOR-NOR structure.
- Power/density
- Ratio of the density (number of gates) to the power (current and
therefore heat) possible in a given technology.
- Power option
- Macro option that provides extra current to drive additional fan-out
loads without altering the function or the propagation delay. Used on
older families of arrays.
- POWER_SUPPLY
- This chip macro parameter is available only to ECL or standard-reference
ECL/TTL mixed circuits. For 100% ECL circuits it specifies the standard
-5.2V (STD5) or -4.5V (STD4) supply or the +5V reference supply (5VREF).
For mixed circuits it specifies either -5.2V or -4.5V. It is used with
PRODUCT_GRADE to determine AMCCANN delay file values.
- PRODUCT_GRADE
- This chip macro parameter is used to identify a circuit as MILitary
or COMmercial. Along with POWER_SUPPLY, it is used by AMCCANN to determine
the contents of the time delay files (depending on the library).
- PRODUCT_NAME
- An array or circuit code name used to identify a design. It appears
as a parameter on the chip macro.
- PROM
- Programmable read-only memory; "AND" array, pre-programmed (at the
factory), n inputs, 2**n product terms; "OR" array, user-programmable,
any of the product terms can be ORed to the y outputs.
- Propagation delay
- The time it takes a signal to pass through a macro from input to output,
specified in typical time in the macro listing in the AMCC Design Manuals.
- ps
- Picosecond, 10-12 sec.
- Pseudo-ECL
- ECL operating in the TTL voltage range, using +5V and GND. More properly
called +5V REF ECL.
Q
- Q
- True output of a flip/flop or latch.
- QN
- Complementary output of a flip/flop or latch.
R
- R
- Reset Q output of a latch or flip/flop to FALSE, usually = 0.
- Radiation-hard
- RAD-hard Degree of resistance from radiation effects.
- RAM
- Random Access Memory, used to refer to Readable - Writable Memory
- Rising-edge active
- A flip/flop or device that can change state on the rising edge of
the active clock and is static during the falling edge of the active
clock.
- ROM
- Read Only Memory
- Routing channels
- Paths that can be used during layout to complete circuit interconnections.
that replaces the static current source of the emitter follower. This
allows lower power, higher drives, and reduced skews.
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