Specifications

CHAPTER 5: PLACE & ROUTE
PRESERVING ASSIGNMENTS THROUGH BACK-ANNOTATION
ALTERA CORPORATION INTRODUCTION TO QUARTUS II ■ 109
Many of the Exploration Space modes allow you to specify the degree of
effort you want DSE to spend in fitting the design; however, increasing the
effort level usually increases the compilation time. Custom exploration
mode allows you to specify various parameters, options, and modes and
then explore their effects on your design.
The Signature modes allow you to explore the effect of a single parameter on
your design and its trade-offs for f
MAX
, slack, compile time, and area. In the
Signature modes, DSE tests the effects of a single parameter over multiple
seeds, and then reports the average of the values so you can evaluate how
that parameter interacts in the space of your design.
DSE also provides a list of Optimization Goal options, which allow you to
specify whether DSE should optimize for area, speed, or for negative slack
and failing paths.
In addition, you can specify Search Method options, which provide
additional control over how much time and effort DSE should spend on the
search.
After you have completed a design exploration with DSE, you can create a
new revision from a DSE point. You can then close DSE and open the project
with the new revision from within the Quartus II software.
Preserving Assignments through
Back-Annotation
You can preserve resource assignments from the last compilation by back-
annotating assignments to any device resource. You can back-annotate all
the resource assignments in a project; you can also back-annotate the size
f
For Information About Refer To
Using the Design Space Explorer “Design Space Explorer” in the Quartus II
Handbook, vol. 2, on the Altera web site
Parameters and settings for optimizing
performance
“Design Optimization for Altera Devices” in
the Quartus II Handbook, vol. 2, on the
Altera web site