Answers Database

M1 CPLD: How does the CPLD Auto Device Selection Work


Record #2704

Product Family:  Software

Product Line:  CPLD Implementation

Problem Title:
M1 CPLD: How does the CPLD Auto Device Selection Work


Problem Description:
Keywords: Fitter, auto, auto selection, auto device selection

Urgency: Standard

General Description:

How does the CPLD fitter automatically chooses a device for the
target design?


Solution 1:

If you select XC9500 as the Family in the Part Selector window
and choose "All" for Device, Package and Speed Grade filters,
the software is free to choose any device in the selected
family.


Auto Device, Package and Speed Grade Selection

If you do not choose "All" for all the filters, but just for
one or two of them, the software tries to fit your design
within the range of possible devices you have selected by using
the following selection criteria:

1. First, the software selects the smallest die.
2. Second, the software selects the smallest package.
3. Third, the software selects the fastest speed-grade device
   for the selected device.


Auto Package and Speed Grade Selection for a selected Device


The software will continue to try fitting your design into one
of the possible range of selected devices until the first
usable one is found or until there are no more devices to try.



End of Record #2704