Answers Database

bitgen m1.2.11: Configuration Address Pins A18 - A21 are optional; xc4000EX only


Record #1984

Product Family:  Software

Product Line:  Merged Core

Problem Title:
bitgen m1.2.11: Configuration Address Pins A18 - A21 are optional;
xc4000EX only



Problem Description:
The Configuration Address Pins A18, A19, A20, A21 are only activated
by a bitgen option -g addresslines:<value>.  The value specifies
the total number of address lines to be activated.  By default this
number is 18.  Since these lines are optional, they will act like
unconfigured IOs until the portion of the bitstream to activate them
is received.  This means that A18-A21 will float high at the
beginning of configuration.  For Master Parallel Up configuration
they need to be low from the beginning.  This can be accomplished
with a pulldown.


Solution 1:

In order to set the option to activate the upper address lines
from the Design Manager GUI, you will need to perform the
following steps :

1.  Create a project for your design.

2.  From the Utilities pull-down menu select Template Manager.

3.  Select the "xc4000" Family from the top pull down menu and
    then select the "Configuration Template" buttton from the
    Template Manager window.

4.  Select the New button and specify a name for your personal
    configuration template.

5.  Being sure your template name is selected in the "Template
    List" window and press the "Customize" button.

6.  Once the Customize window appears, type into the following
    fields (WEBIMAGE 1:Template Manager Customize Window) :

    Program Name : bitgen
    Program Options : -g addresslines:22

7.  Press the "Set" button and then select "OK".

8.  Press the "Edit" button and select all other configuration
    options you wish to use for your design.

9.  Close the Tamplate Manager

10. Implement your design selecteing from the Implement Options
    window the configuration template you have just created.


For more information on the Template Manager consult the
"Design Manager/Flow Engine Refernce/User Guide" from your
Dynatext On-line Document Browser.



Solution 2:

The value specifies the total number of address lines to be
activated.  By default this number is 18.  If you wanted A18 - A21 to
be activated the bitgen syntax would be:

bitgen -g addresslines:22



End of Record #1984