Answers Database

MAP: What is an MDF file?


Record #3196

Product Family:  Software

Product Line:  Merged Core

Problem Title:
MAP: What is an MDF file?


Problem Description:
Keywords: map, mdf

Urgency: standard

General Description:
What is an MDF file?


Solution 1:

The ".MDF" extension stands for "Mapper Data File".  The MDF file
contains information about how gates implemented using more than
one LUT are composed.  This information is used as a "hint"
to Map when Map is run with the guide (-gf) option.

For 4-input gates, MDF data is generated only if more than one
LUT is used to implement the gate.  If Map implements the gate in
a single 4-input LUT, the decomposition information is not needed,
and is not generated.

As an example, say you have a 5-input AND gate.  Depending on how
this 5-input function was implemented, the MDF file could indicate
that the logic function was separated into a combination of a
3-input F-LUT and a 3-input H-LUT, or a combination of a 4-input
F-LUT and 2-input H-LUT.





Solution 2:

When you specify -gf option or using the browse button
in design manager, map will pick up the .mdf by name
association.  The MDF file name is implied by the guided NCD
name.  For example, if you use fred.ncd as the guide file
then the mapper looks for a file (in the same directory)
called fred.mdf.  However, in the design manager, the .ncd
file is called map.ncd, so the .mdf file should be called map.mdf.



End of Record #3196