| Number | 226
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| Category | errata
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| Synopsis | Illegal to assign mintypmax expression to parameter?
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| State | lrmdraft
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| Class | errata-discuss
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| Arrival-Date | Dec 23 2002
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| Originator | "Brad Pierce" <Brad.Pierce@synopsys.com>
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| Release | 2001b
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| Environment |
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| Description |
According to the V2K BNF, the following module is illegal -- module m_illegal ; parameter p = 1:2:3; endmodule and the following module is legal -- module m_legal ; parameter p = (1:2:3); endmodule Was that the intent? Tools seem to be just as happy with m_illegal as with m_legal. If m_illegal is indeed illegal, how about adding an example? Likewise, according to the BNF, the following parameter assignments are illegal #(.p(1:2:3)) #(1:2:3) and the following are legal #(.p((1:2:3)) #((1:2:3)) but the tools seem to be just as happy with the illegal versions. -- Brad |
| Fix |
In A.2.4 REPLACE param_assignment ::= parameter_identifier '=' constant_expression WITH param_assignment ::= parameter_identifier '=' constant_mintypmax_expression and in Syntax 12-2 and A.4.1 REPLACE ordered_parameter_assignment ::= expression named_parameter_assignment ::= '.' parameter_identifer '(' [ expression ] ')' WITH ordered_parameter_assignment ::= mintypmax_expression named_parameter_assignment ::= '.' parameter_identifer '(' [ mintypmax_expression ] ')' |
| Audit-Trail |
From: Shalom.Bresticker@motorola.com To: etf-bugs@boyd.com Cc: Subject: Re: errata/226: PROPOSAL - Illegal to assign mintypmax expression to parameter? Date: Mon, 23 Jun 2003 08:37:52 +0300 (IDT) I do not accept that explanation. Historically, specparams were only allowed in specify blocks. Only in 1364-2001 were they allowed also outside of specify blocks. Parameters were always allowed min:typ:max expressions. The only question is about the parentheses. As already pointed out, even the 1364-1995 tools allow them without parentheses in certain situations. Shalom > Keep the existing behaviour. Section 3.11.3 describe the difference between parameters and specify parameters and it states that specify parameters is a special type of parameter intended only for providing timing and delay values. Specparams allow the use of mintypmax_expression but parameter declarations does not. Table 8 in section 3.11.3 is clearly stating that parameters may not be assigned specparams so it is ok that they are declared differently. > Parameters may be assigned constant_expressions which include constant_primary and constant_primary include (constant_mintypmax_expression), hence example m_legal is OK but m_illegal is not. > > Add the following line in the last example in section 3.11.1: > parameter p = (1:2:3); //parenthesis required since constant_mintypmax_expression is not allowed. > http://boydtechinc.com/cgi-bin/issueproposal.pl?cmd=view&pr=226 -- 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 Analyzed by etf@boyd.com on Mon Aug 25 03:46:14 2003 This is just to delete old proposal. From: Shalom.Bresticker@motorola.com To: Brad.Pierce@synopsys.com Cc: etf-bugs@boyd.com Subject: Re: errata/226: PROPOSAL - Illegal to assign mintypmax expression to parameter? Date: Sat, 20 Sep 2003 22:35:21 +0300 (IDT) I oppose the proposal. We have already concluded that the BNF is faulty and does not correctly describe the tool behaviors, which allow the so-called illegal cases. Similarly, the statement that "Specparams allow the use of mintypmax_expression but parameter declarations do not" is not correct. At the Aug. 11 ETF meeting, we rejected an identical proposal. Shalom > APPEND the following line to the examples at the end > of 3.11.1 > > parameter p = (1:2:3); //parenthesis required since constant_mintypmax_expression is not allowed > > Answer to original question: The behavior is correct as described. Section 3.11.3 describes the difference between parameters and specify parameters and it states that a specify parameter is a special type of parameter intended only for providing timing and delay values. Specparams allow the use of mintypmax_expression but parameter declarations do not. Table 8 in section 3.11.3 is clearly stating that parameters may not be assigned specparams, so it is OK that they are declared differently. > Parameters may be assigned constant_expressions, which include constant_primary and constant_primary, which includes (constant_mintypmax_expression), hence example m_legal is OK but m_illegal is not. -- 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 From: "Brad Pierce" <Brad.Pierce@synopsys.com> To: <etf-bugs@boyd.com> Cc: Subject: RE: errata/226: PROPOSAL - Illegal to assign mintypmax expression to parameter? Date: Sun, 21 Sep 2003 08:54:34 -0700 Shalom, You are completely right. Thank you for pointing out my mistake, because I seem to have lost my memory of that ETF meeting. I'm glad there are meeting minutes (and Shalom), because, according to the meeting minutes I have an action item to correct the BNF! Thanks again, -- Brad Date: Fri, 3 Oct 2003 22:41:43 -0700 From: Brad.Pierce@synopsys.com To: etf-bugs@boyd.com Subject: errata/226: PROPOSAL - Illegal to assign mintypmax expression to parameter? Precedence: bulk In A.2.4 REPLACE param_assignment ::= parameter_identifier '=' constant_expression WITH param_assignment ::= parameter_identifier '=' constant_mintypmax_expression and in Syntax 12-2 and A.4.1 REPLACE ordered_parameter_assignment ::= expression named_parameter_assignment ::= '.' parameter_identifer '(' [ expression ] ')' WITH ordered_parameter_assignment ::= mintypmax_expression named_parameter_assignment ::= '.' parameter_identifer '(' [ mintypmax_expression ] ')' http://boydtechinc.com/cgi-bin/issueproposal.pl?cmd=view&pr=226 Date: Sat, 4 Oct 2003 11:26:35 -0700 From: Brad Pierce <Brad.Pierce@synopsys.com> To: Shalom Bresticker <Shalom.Bresticker@motorola.com> Subject: RE: errata/226: PROPOSAL - Illegal to assign mintypmax expression to parameter? When the proposal mechanism is working again, I will update this to also replace in A.2.4 defparm_assignment ::= hierarchical_parameter_identifier '=' constant_expression with defparm_assignment ::= hierarchical_parameter_identifier '=' constant_mintypmax_expression October 6, 2003: Discussed in ETF. Opposition to extension of defparam statement. Unmodified proposal (no defparams) was passed. Brad will file a new issue for the defparam change (#493). |
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