Re: Support for values x and z

Jayaram Bhasker (jbhasker@Cadence.COM)
Wed, 10 Mar 1999 09:14:42 -0500 (EST)

Oops, I forgot to add few other statements to the proposal. Here is
an updated one.

Here is an UPDATED proposal, to add to section 5, on how x and z values are to be
interpreted for synthesis.

--------------------------

5.5 Support for meta-logical values, x and z

The value x may be used only as a primary on the RHS of an assignment
to indicate
a dont care value for synthesis.

The value x may be used in case item expressions in a casex statement to
imply a dont care value for synthesis.

The value x may be used in a case item expression in a case statement; however
such a branch is never expected to occur for synthesis.

The value x shall not be used with any
operators or mixed with other expressions.

The value z may be used only as a primary on the RHS of an assignment to
infer a three-state driver as described in section 5.4.

The value z (or ?) may be used in case item expressions for casex and casez
statements to imply a dont care value for synthesis.

The value z may be used in a case item expression of a case statement; however
such a branch is never expected to occur for synthesis.

The value z shall not be used with any operators or mixed with other expresions.

-------------------------

Please provide your comments on this UPDATED proposal by March 15.

- bhasker

----- Begin Included Message -----

X-Authentication-Warning: server.eda.org: majordom set sender to owner-vlog-synth@eda.org using -f
Date: Mon, 8 Mar 1999 16:12:11 -0500 (EST)
From: Jayaram Bhasker <jbhasker>
To: vlog-synth@eda.org
Subject: Support for values x and z
X-Sun-Charset: US-ASCII
Sender: owner-vlog-synth@eda.org
Content-Type: text
Content-Length: 686

Here is a proposal, to add to section 5, on how x and z values are to be
interpreted for synthesis.

--------------------------

5.5 Support for non-logical values, x and z

The value x may be used only as a primary on the RHS of an assignment
to indicate
a dont care value for synthesis.

The value x shall not be used with any
operators or mixed with other expressions.

The value z may be used only as a primary on the RHS of an assignment to
infer a three-state driver as described in section 5.4.

The value z shall not be used with any operators or mixed with other expresions.

-------------------------

Please provide your comments on this proposal by March 15.

- bhasker

----- End Included Message -----