Answers Database

XC7300: MR (Master Reset) Pin can optionally be used as an input


Record #1801

Product Family:  Hardware

Product Line:  7300

Problem Title:
XC7300: MR (Master Reset) Pin can optionally be used as an input


Problem Description:
The XC7318, XC7336, XC7354 and XC73144 devices have a
Master Reset pin, which can optionally be specified as a user
input.

The default behavior for the MR pin in the above devices is
the Master Reset functionality.  This will invoke the full
initialization of the respective 7300 device when pulsed.
If you don't require this reset operation except for at
powerup, then you can optionally use this pin as an input.



Solution 1:

To use the MR pin as an input, you must specify the MRINPUT
global attribute.

In a schematic:
---------------
Attach the attribute MRINPUT=ON to any input buffer in the
design.  The name of the attribute is MRINPUT and the
value/description is ON.  This will disable the Master Reset
functionality of the MR pin, and allow it to be used as a
regular input pin during normal operation.



Solution 2:

In an ABEL file:
----------------

Use the following XEPLD Property statement in the Declarations
section of the Abel file.

XEPLD Property 'MRINPUT';



End of Record #1801