RE: sv-bc19-40


Subject: RE: sv-bc19-40
From: Jacobi, Dan (dan.jacobi@intel.com)
Date: Mon Jan 06 2003 - 01:26:16 PST


Sorry for the late response, haven't been in for the last two weeks.

This looks like my mistake the posedge and negedge can not be parsed via the
edge_control_specifier token.
I suggest we drop this issue (labeled SV-BC-19-40)

P.S.
does any body know why no more than TWO edge descriptors can be used to
describe the value transitions meaning that the following example is
considered legal
        edge[01, 0x] clr
and the following example is not considered legal
        edge[01, 0x, x1] clr

Dan Jacobi

-----Original Message-----
From: Shalom Bresticker [mailto:Shalom.Bresticker@motorola.com]
Sent: Sunday, December 29, 2002 10:09 AM
To: sv-bc@eda.org
Subject: sv-bc19-40

sv-bc19-40 says,

timing_check_event_control ::=
   posedge
   | negedge
   | edge_control_specifier

edge_control_specifier ::= edge [ edge_descriptor [ , edge_descriptor ]
]

The ?posedge? and ?negedge? keywords are redundant due to the fact that
they can be parsed when parsing the
?edge_control_specifier? token.

This issue is labeled as SV-BC-19-40.

***

I don't understand this comment.

This is specifically discussed in 15.4 of 1364-2001.
It says there,

"The posedge and negedge keywords can be used as a shorthand for certain
edge-control specifiers. For example, the construct:

posedge clr

is equivalent to the following:

edge[01, 0x, x1] clr

Similarly, the construct

negedge clr

is the same as the following:

edge[10, x0, 1x] clr

However, edge-control specifiers offer the flexibility to declare edge
transitions other than posedge and negedge. "

That is, posedge and negedge could be written with edge only,
but they deliberately exist for the sake of convenience.

--
Shalom Bresticker                           Shalom.Bresticker@motorola.com
Design & Reuse Methodology                             Tel: +972 9 9522268
Motorola Semiconductor Israel, Ltd.                    Fax: +972 9 9522890
POB 2208, Herzlia 46120, ISRAEL                       Cell: +972 50 441478

"The devil is in the details."



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