LPM Quick Reference Guide

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