LPM Quick Reference Guide
December 1996

LPM Features
The primary objective for the LPM is to enable architecture-independent
design without sacrificing efficiency. The LPM meets the following key
criteria:
n
Architecture-independent design entry
—Designers can work with LPM
functions during design entry and verification without specifying the
target architecture. Design entry and simulation tools remain
architecture-independent, relying on the synthesis or fitting tools to
efficiently map the design to various architectures.
n
Efficient design mapping
—The LPM allows designers to create
architecture-independent designs without sacrificing efficiency. The
IC vendor is responsible for the mapping of LPM functions; thus,
optimum solutions are guaranteed.
n
Tool-independent design entry
—The LPM enables designers to migrate
designs between EDA tools while maintaining a high-level logic
description of the functions. For example, designers can use one
vendor’s tool for logic synthesis and another vendor’s tool for logic
simulation.
n
Specification of a complete design
—LPM functions completely specify
the digital logic for any design. Designers can create new functions
with LPM functions.
LPM Functions
The LPM presently contains 25 functions. Despite its small size, the LPM
can duplicate the functionality of other design libraries that contain many
more functions; each function contains parameters that allow it to expand
in many dimensions. For example, the
lpm_counter
function allows the
user to create counters with widths ranging from 1 to 256 bits.
In addition to width, the user can specify the features and functionality of
the counter. For example, parameters indicate whether the counter counts
up or down, or loads synchronously or asynchronously. Thus, the single
lpm_counter
function can replace over thirty 74-series counters