Unit installation

Glossary
Altera Corporation 307
Glossary
Glossary
The EAB is fed by row interconnect paths
and a dedicated input bus.
embedded cell (EC) A memory element
that exists in the embedded array of a
FLEX 10K device, and which can
implement memory (RAM or ROM) or
combinatorial logic. An Embedded Array
Block (EAB) consists of a group of 8
embedded cells that can implement a
memory block of 256 × 8, 512 × 4, 1,024 × 2,
or 2,048 × 1 bits. Each embedded cell within
an EAB implements up to 256 bits of
memory. Depending on the depth of the
memory, up to 8 of the embedded cells in
an EAB have outputs. For memory blocks
of 256 × 8, 512 × 4, 1,024 × 2, or 2,048 × 1 bits,
an EAB has 8, 4, 2, or 1 outputs,
respectively.
Embedded cells have ÒnumbersÓ of the
format EC<number>_<row letter>, where
<number> ranges from 1 to 8 and <row
letter> consists of the row letter of the EAB.
EPLD Erasable Programmable Logic
Device, i.e., an Altera device that is a
member of the Classic, MAX 5000,
MAX 7000, or MAX 9000 device families.
EPROM Erasable Programmable Read-
Only Memory. A form of reprogrammable
semiconductor memory in which the
contents (program) can be erased by
subjecting the device to ultraviolet light of
the proper wavelength.
evaluated function An mathematical
function that evaluates an arithmetic
expression and returns a value based on
one or more arguments. The AHDL Define
Statement can be used to create evaluated
functions. The following example shows
the definition of the evaluated function
MAX:
DEFINE MAX(a,b) = (a > b) ? a : b;
expander product term A single product
term with an inverted output that feeds
back into the Logic Array Block (LAB) of a
MAX 5000, MAX 7000, or MAX 9000
device.
An uncommitted expander product term
that can be shared with other logic cells in
the same LAB is called a shareable
expander; a product term that has been
shared in this manner is called a shared
expander.
In MAX 7000 and MAX 9000 devices only,
an expander product term that is
ÒborrowedÓ from an adjacent logic cell in
the same LAB is called a parallel expander.
extension see filename extension.
F
family-specific mega- or macrofunction An
Altera-provided mega- or macrofunction
that contains logic optimized for the
architecture of a specific device family.
The functionality of a family-specific mega-
or macrofunction is always the same,
regardless of the device family for which it
is designed. However, the actual
primitives and nodes used within the
mega- or macrofunction file can vary from
family to family to take advantage of
different device architectures, thus
providing higher performance and/or
more efficient implementation.
81_GSBOOK.fm5 Page 307 Tuesday, October 14, 1997 4:04 PM