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ngd2edif: What's the bus designator in the edif file produced by ngd2edif, and why is it buses don't have the designator when ngdanno run with the .ngm file


Record #7233

Product Family: Software

Product Line: FPGA Implementation

Product Part: ngd2edif

Product Version: 2.1i

Problem Title:
ngd2edif: What's the bus designator in the edif file produced by ngd2edif, and why is it buses don't have the designator when ngdanno run with the .ngm file



Problem Description:
Urgency: Standard

Problem Description:

The edif file produced by ngd2edif contains designators on single bit Input or Output port, such as the following:
(port shout
          (direction OUTPUT)
          (designator "223")
          )

However, if the Input or Output are buses, the designator may not show up for
the bus ports in the edif file.

What does the designator mean? and why is it the buses sometimes don't have
the designator definition in the edif file produced by ngd2edif?


Solution 1:

The designator indicates the pin location of the Input or Output port. The above example shows that Output port shout is on P223.

For bus ports, the logical back annotation, which is the annotation running with ngm
file (ngdanno <design>.ncd <design>.ngm), the designators will not be written in the
edif file, because the EDIF itself does not provide a way to specify a designator for each member of the port array.

In physical back annotation, which is the annotation running without ngm file
(ngdanno <design.ncd>), the bus port is reconstructed, and the designators will
be attached to each bus port.




End of Record #7233 - Last Modified: 08/10/99 11:37

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