[sv-ec] parenthetical statements

There is nothing in IEEE Standards Manual to indicate that parenthetical
statements are not normative, as far as I know, as long as they are
worded in normative language, just like any other statements in the
standard.

Shalom

> -----Original Message-----
> From: owner-sv-ec@server.eda.org [mailto:owner-sv-ec@server.eda.org]
On
> Behalf Of Brad Pierce
> Sent: Thursday, May 11, 2006 9:08 PM
> To: sv-ec@server.eda.org
> Subject: Re: [sv-ec] semantics of wildcard bins
> 
> Are parenthetical comments normative?
> 
> >I would much rather remove the parenthetical comment.
> 
> It would be a good general policy to remove parenthetical comments.
See
> also --
> 
>    http://eda.org/svdb/bug_view_page.php?bug_id=695
>    http://eda.org/svdb/bug_view_page.php?bug_id=1108
>    http://eda.org/svdb/bug_view_page.php?bug_id=1425
> 
> -- Brad
> 
> 
> 
> -----Original Message-----
> From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
> Ryan, Ray
> Sent: Wednesday, May 10, 2006 12:42 PM
> To: Bresticker, Shalom; sv-ec@eda.org
> Subject: RE: [sv-ec] semantics of wildcard bins
> 
> Hi Shalom,
> 
> 
> For #2 the sample exclusion is different from the semantics of '==?'.
> 
> The '==?' operator is asymmetric. The '?', 'x' or 'z' values
> are wildcards in the right operand. An 'x' in the right operand
> matches any value in the left operand (including 'x' or 'z').
> An 'x' in the left operand only matches a wildcard ('x' 'z' or '?')
> in the right operand.
> 
> When applied to the context of bin matching, the bin value
> correspond to the right operand (wildcards recognized) and
> the sample value is the left operand. If the sample value
> contains an 'x', and the corresponding bit of the bin value
> is '?' (as in my example) application of 'sample ==? bin_value'
> would yield TRUE - indicating a match and presumably the bin
> should be incremented.
> 
> However, the LRM text seems to state that if the SAMPLED value
> contains an 'x' or 'z' value, the sample value is excluded -
> and thus the bin would NOT be incremented.
> 
> I would expect the behavior to be that of the '==?' operator and
> the bin should be incremented. That is, a wildcard matches any
> value not just 1 or 0.
> 
> Ray
> 
> > -----Original Message-----
> > From: Bresticker, Shalom [mailto:shalom.bresticker@intel.com]
> > Sent: Wednesday, May 10, 2006 4:15 AM
> > To: Ryan, Ray; sv-ec@server.eda.org
> > Subject: RE: [sv-ec] semantics of wildcard bins
> >
> > Hi, Ray.
> >
> > As a user reading this section for the first time, here are
> > the interpretations I would come to as answers to your questions:
> >
> >
> > > -----Original Message-----
> > > From: owner-sv-ec@server.eda.org
[mailto:owner-sv-ec@server.eda.org]
> > On
> > > Behalf Of Ryan, Ray
> > > Sent: Wednesday, May 10, 2006 3:49 AM
> > > To: sv-ec@server.eda.org
> > > Subject: [sv-ec] semantics of wildcard bins
> > >
> > > The last last paragraph of the section on wildcard bins (18.4.3)
> > states:
> > >
> > > "A wildcard bin definition only considers 2-state values; sampled
> > values
> > > containing X or Z are excluded. Thus, the range of values
> > covered by a
> > > wildcard bin is established by replacing every wildcard
> > digit by 0 to
> > > compute the low bound and 1 to compute the high bound."
> > >
> > >
> > > 1) The statement about the range of values is not right or is
> > confusing.
> > >
> > >    For example:
> > > 	wildcard bins bx = { 4'b?0?0 };
> > >    This does not cover the values in the range 0000 to 1010. It
> > doesn't
> > > cover 0001.
> > >
> >
> > [Shalom] Agree.
> >
> >
> > > 2) What does it mean that sampled values containing X or Z are
> > excluded.
> > >
> > >    For example:
> > > 	wildcard bins bx = { 4'b?0?0 };
> > >    I would expect that if the sample value is:
> > >         0000	- increment the bin count
> > >         1000      - increment the bin count
> > >         0001      - don't increment
> > >         000X 	- don't increment
> > >         0010      - increment
> > >         00X0      - increment
> > >         00Z0      - increment
> > >     However, the text seems to indicate that the last two sample
> > values
> > > are excluded and
> > >     so don't increment the bin count.
> > >
> >
> > [Shalom] Yes, they are excluded. The text explicitly says
> > that the ? is a wildcard for 0 and 1 and that it works like ==?.
> >
> >
> > > 3) How many bins are created for
> > >     	wildcard bins bx[] = { 4'b?0?0, 4'b?000, 4'b00?0 }
> > >    I would expect that 3 bins are created.
> > >
> >
> > [Shalom] Agree.
> >
> >
> > > 4) How are wildcard ignore_bins handled?
> > >     For example:
> > > 	bins BA[2] = { 2'b00, 2'b1x };
> > >       bins BB[2] = { 2'b10, 2'b0x };
> > > 	wildcard bins BC = { 2'b0?, 2'b11 }
> > >       wildcard ignore_bins ivals = { 2'b00, 2'b?0, 2'b0? };
> > >       ignore_bins vals = { 2'b01, 2'b00, 2'b0x, 2'b0z };
> > >
> > >     The ignore value 2'b00 will be removed from the first BA bin
> > causing
> > > the
> > >     bin to be ignored.
> > >     Will the ignore value 2'b?0 remove the 2'b10 value from BB ?
> >
> > [Shalom] Yes.
> >
> >
> > >     Will the list of values in the last ignore_bins remove the
> > wildcard
> > >     value 2'b0 from BC ?
> >
> > [Shalom] Yes.
> >
> > Two more editorial quibbles:
> >
> > The first example in this section is called g12_16 and
> > increments "when the sampled value is between 12 and 16".
> > Actually the range is only 12-15.
> >
> > Also, the first and third paragraphs in this section refer to
> > "wildcard bins", with both in Courier font. As a reader, I
> > would be in doubt whether or not this implies that 'wildcard'
> > may only be used with 'bins'
> > and not with 'ignore_bins' and 'illegal_bins' (going back to
> > the rule that the BNF does not contain all the information
> > and the text supplements it). The simplest correction would
> > be to de-Courierize "bins' in those two places.
> >
> > Shalom
> >
> >