RE: [sv-ac] What is the meaning of 'match' here?

Hi Surya,

 An example of an erroneous match is:

 sequence S(local inout bit v);
 (a[*0:3])
  or
 (c, v = 1)
endsequence

note that "a[*0:3]" admits the empty match. So the sequence is illegal.

Doron


>>-----Original Message-----
>>From: Surya Pratik Saha [mailto:spsaha@cal.interrasystems.com]
>>Sent: Wednesday, December 24, 2008 9:52 AM
>>To: Bustan, Doron
>>Cc: sv-ac@server.eda.org
>>Subject: Re: [sv-ac] What is the meaning of 'match' here?
>>
>>Hi Doron,
>>Thanks for the clarification. But I am not clear about an 'empty match'
>>as LRM mentioned:
>>
>>"It shall be an error for an instance of a named sequence with an inout
>>or output local variable formal argument to admit an empty match."
>>
>>Can you please give us an exampled regarding this.
>>
>>Regards
>>Surya
>>
>>
>>
>>-------- Original Message  --------
>>Subject: Re:[sv-ac] What is the meaning of 'match' here?
>>From: Bustan, Doron <doron.bustan@intel.com>
>>To: Surya Pratik Saha <spsaha@cal.interrasystems.com>,
>>sv-ac@server.eda.org <sv-ac@eda.org>
>>Date: Wednesday, December 24, 2008 1:06:56 PM
>>> Hi Surya,
>>>
>>> At 16.7 it says "The sequence feature provides the capability
>>> to build and manipulate sequential behaviors. The simplest sequential
>>behaviors are linear. A linear
>>> sequence is a finite list of SystemVerilog boolean expressions in a
>>linear order of increasing time. The linear
>>> sequence is said to match along a finite interval of consecutive clock
>>ticks provided the first boolean expression
>>> evaluates to true at the first clock tick, the second boolean expression
>>evaluates to true at the second
>>> clock tick, and so forth, up to and including the last boolean
>>expression evaluating to true at the last clock
>>> tick. A single boolean expression is an example of a simple linear
>>sequence, and it matches at a single clock
>>> tick provided the boolean expression evaluates to true at that clock
>>tick.
>>> More complex sequential behaviors are described by SystemVerilog
>>sequences. A sequence is a regular
>>> expression over the SystemVerilog boolean expressions that concisely
>>specifies a set of zero, finitely many,
>>> or infinitely many linear sequences. If at least one of the linear
>>sequences from this set matches along a finite
>>> interval of consecutive clock ticks, then the sequence is said to match
>>along that interval."
>>>
>>> An example of an erroneous match is:
>>>
>>> sequence S(local output bit v);
>>> (a[->1], v = 1)
>>> or
>>> (b[->1]);
>>> endsequence
>>>
>>> in any interval of a computation where "b" appears before "a", there is
>>a match of S to the interval, but the value of "v" is undefined. This is
>>considered an error.
>>>
>>>
>>>
>>>
>>>>> -----Original Message-----
>>>>> From: owner-sv-ac@server.eda.org [mailto:owner-sv-ac@server.eda.org]
>>On
>>>>> Behalf Of Surya Pratik Saha
>>>>> Sent: Wednesday, December 24, 2008 7:55 AM
>>>>> To: sv-ac@server.eda.org
>>>>> Subject: [sv-ac] What is the meaning of 'match' here?
>>>>>
>>>>> Hi,
>>>>> As per 2009 SV draft LRM:
>>>>> "It shall be an error if there exists a match of the named
>>>>> sequence for which an inout or output local variable formal argument
>>is
>>>>> unassigned at the completion
>>>>> of the match. At the completion of a match of the instance of the
>>named
>>>>> sequence, the value of
>>>>> the inout or output local variable formal argument shall be cast to
>>the
>>>>> type of and assigned to the
>>>>> local variable whose reference is the associated actual argument."
>>>>>
>>>>> What is the meaning of 'match' here. One example snippet will be
>>better.
>>>>>
>>>>> --
>>>>> Regards
>>>>> Surya
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> This message has been scanned for viruses and
>>>>> dangerous content by MailScanner, and is
>>>>> believed to be clean.
>>>>>
>>>>>
>>>>> --
>>>>> This email was Anti Virus checked by Astaro Security Gateway.
>>>>> http://www.astaro.com
>>>>>
>>> ---------------------------------------------------------------------
>>> Intel Israel (74) Limited
>>>
>>> This e-mail and any attachments may contain confidential material for
>>> the sole use of the intended recipient(s). Any review or distribution
>>> by others is strictly prohibited. If you are not the intended
>>> recipient, please contact the sender and delete all copies.
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>

---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.