Tips on using Quartus Library Parameterized Modules (LPM)

1. LPM variations and instances in the delay_collatz_schematic.bdf schematic

The picture on slide 7 of lab tutorial E02 does not always indicate which 
LPMs are made use of to produce the IP variations and instances thereof in 
the schematic. The following table provides that information, together with 
the relevant category under IP Catalog / Library / Basic Functions: 

   LPM           IP variations   instances       category

   LPM_ADD_SUB   addc.qip        inst            Arithmetic
                 d_add.qip       inst9
   LPM_COMPARE   stop_test.qip   inst1           Arithmetic
   LPM_CONSTANT  zero_16.qip     inst18, inst19  Miscellaneous
   LPM_MUX       mux1_16.qip     inst15, inst16  Miscellaneous
                 mux1_32.qip     inst5, inst6
   LPM_CLSHIFT   reg_16.qip      inst10          Miscellaneous
                 reg_32.qip      inst14 

  Furthermore, a few other elements in the schematic are instances of 
nonparameterized modules, which may be retrieved by the Symbol tool from the 
$QUARTUS_ROOTDIR/libraries/primitives library paths. The following table 
traces those instances back to the library modules they derive from: 

   module        instances              path

   not           inst2                  logic
   or2           inst3                  logic
   and2          inst7                  logic
   dff           inst8                  storage
   input         CLK, start, x0[15..0]  pin
   output        done, delay[15..0]     pin
   wire          inst11                 buffer
   gnd                                  other
   vcc                                  other


2. Problem: MegaWizard IP window size when defining IP variations of LPM

According to the tutorial on Using Library Modules in VHDL Designs, 
Section 4, IP variations of LPMs out of the IP Catalog may be defined 
by means of the MegaWizard Plug-in Manager. This process goes through 
a sequence of six windows, of varying size, where the user selects the 
specific values for the desired IP variation. A problem that may occur 
is that of a seemingly very slow progress of the MegaWizard IP, to the 
extent that the process may get stuck at some window in the sequence. 

  Surprising as it may seem, the problem is caused by a GUI bug! Namely, 
an insufficient MegaWizard window size makes scrollbars show up that give 
rise to the trouble. The simple solution is that of resizing the window, 
see the post by Lance on 20 May 2015 (4 years agp) in this discussion: 

   https://forums.intel.com/s/question/0D50P00003yyRIkSAM

N.B. Beware: the MegaWizard IP window size may change throughout the sequence 
of steps to define an IP variation, therefore an initial window resizing that 
suffices to let the troublesome scrollbars disappear, following O'Hill, may 
prove insufficient at some subsequent step... in such a case, further widen 
the window.

--

   Author: Giuseppe Scollo, University of Catania, DMI
   Version: 3
   Date: 12 October 2019