RAIL Revision Or Appendage Document  (ROAD)

ROAD ID#:       13.1
ISSUE TITLE:    DC net GND is reserved
REQUESTER:      John Keifer, Intel Corporation
DATE SUBMITTED:   November 19, 1997  December 16, 1997
DATE ACCEPTED BY RAIL WORKGROUP:  December 18, 1997

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

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

STATEMENT OF THE ISSUE:

GND is regularly used as a DC net in layout and therefore cannot be a reserved
word.

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

STATEMENT OF THE RESOLVED SPECIFICATIONS:

Remove the GND and POWER reserved names in 2) under "General syntax rules and
guidelines for ASCII RAIL files" so that it reads the following:

| 2)  The following word is reserved and must not be used for
|     any other purposes in the document:
|        NA     - used where data not available.

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

ANALYSIS PATH/DATA THAT LED TO SPECIFICATION:

The preliminary RAIL Parser showed GND as an invalid DC net name.  Analysis of
the latest RAIL spec shows this to be correct based on present intent and
wording.  Based on the fact that standard layouts today in many groups use GND
and GROUND as standard DC net names, these names cannot be used as reserved
words.  Presently the only places in the RAIL spec using GND and POWER are DC
nets and Topologies. Since Topologies allows DC nets to be used, presently
there is no need to have GND and POWER as reserved words.  If necessary, we can
add them back in the future as a specific solution to an improvement in the
RAIL spec rather than guessing now at what might be needed.

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

ANY OTHER BACKGROUND INFORMATION:

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