The GNDH hardmacro which will generate a 
ground signal which you can then use to drive the
'L' pin on the INLAT symbol in order to get the 
transparent latch delay of 7.0ns.



                      ********** SYMBOL gndh **********


                        Total number of Input  pins = 1
                        Total number of Output pins = 2


                                -----------------
                                |             \ |
                                |              \|
                                |     gndh      |
                            IN_0|               |OUT_0
                          ------|               |------
                                |               |TMP_0
                                |               |------
                                |               |
                                |               |
                                |               |
                                -----------------
                                     DEF = HM


******************************************************************************

NOTE that the symbol MUST be called GNDH as that is the name of the 
hardmacro.  The file GNDH.HM MUST be located in the design directory
(the directory where you run PPR) OR in the \XACT\DATA\HMLIB directory.

NOTE also that you MUST connect the pin TMP_0 to the pin IN_0.  This
feedback loop external to the hardmacro is a nuisance which has no
practical functionality, but it is NECESSARY in this case in order
to get PPR to not TRIM the hardmacro and consequently optimize the 
LATCH into an IBUF.

The OUT_0 pin drives the net which you need to connect to the 
'L' pin of the INLAT symbol.  By holding the 'L' pin of the INLAT 
symbol low, you will permanently enable the IOB Latch, thus implementing
in effect a 7.0ns delay buffer.  This delay is what allows us to effectively
improve the SETUP and HOLD time requirements for external signals.

To incorporate the hard macro into your schematic, you need to create a 
symbol for GNDH with symbol attribute "DEF=HM".  If you are creating 
a Viewlogic symbol, the BLOCK type should be changed to "MODULE" to 
indicate that there is no underlying schematic for the symbol.

*

