| Number | 283
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| Category | errata
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| Synopsis | Syntax 2-1: 'dx, 'dz
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| State | lrmdraft
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| Class | errata-simple
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| Arrival-Date | Feb 14 2003
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| Originator | "Brad Pierce" <Brad.Pierce@synopsys.com>
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| Release | 2001b: 2.5.1
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| Environment |
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| Description |
According to Syntax 2-1, a based decimal number can either be something like 12'd1_234_ or something like 12'dx____ 12'dX____ 12'dz____ 12'dZ____ 12'd?____ Section 2.5.1 about integer constants explains what x and z mean in binary, octal and hexidecimal constants, in which they can be used as digits. But the section is silent about the meaning of 'dx and 'dz and about the (sensible) restriction that x and z cannot be used as decimal digits. Is 12'dx the same as 12'bx? Is 12'sdx the same as 12'sbx? -- Brad |
| Fix |
In 2.5.1 before the paragraph about '_', add the following paragraph -- "In a decimal constant, the unsigned number token shall not contain any x, z, or ? digits, unless there is exactly one digit in the token, indicating that every bit in the decimal constant is x or z." and at the end of Example 3 of 2.5.1 add the following line -- 16'sd? // the same as 16'sbz |
| Audit-Trail |
From: Steven Sharp <sharp@cadence.com> To: etf-bugs@boyd.com, Brad.Pierce@synopsys.com Cc: Subject: Re: errata/283: Syntax 2-1: 'dx, 'dz Date: Tue, 18 Feb 2003 14:57:10 -0500 (EST) As you note, x and z cannot be sensibly be combined with decimal digits to create values with some bits known and others unknown. There is not a single decimal digit that decides the value of a particular bit in the result. A decimal constant can still use a single x or z digit to indicate that the entire number is x or z. You are right that there doesn't seem to be a description of this in the text. Steven Sharp sharp@cadence.com From: Shalom Bresticker <Shalom.Bresticker@motorola.com> To: Brad.Pierce@synopsys.com Cc: etf-bugs@boyd.com Subject: Re: errata/283: PROPOSAL - Syntax 2-1: 'dx, 'dz Date: Tue, 30 Sep 2003 18:52:43 +0300 Change "succeeded" to "followed". Add the optional size constant at the beginning. > "An x, z, or ? shall not be used in a decimal > constant except for a single x, z, or ? preceded > by a digital base format and optionally succeeded > by underscore characters, indicating that the > entire number is x or z." -- 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 Fix replaced by Brad.Pierce@Synopsys.com on Sat Oct 25 23:12:05 2003 In 2.5.1 before the paragraph about '_', add the following paragraph -- "In a decimal constant, the unsigned number token shall not contain any x, z, or ? digits, unless there is exactly one digit in the token, indicating that every bit in the decimal constant is x or z." and at the end of Example 3 of 2.5.1 add the following line -- 16'sd? // the same as 16'sbz |
| Unformatted |
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