****************************************************************************** ****************************************************************************** BIRD ID#: 93.1 ISSUE TITLE: Model and Signal Name Limit Extension REQUESTER: Michael Mirmak, Intel Corp. DATE SUBMITTED: November 5, 2004 DATE REVISED: November 21, 2004 DATE ACCEPTED BY IBIS OPEN FORUM: December 10, 2004 ****************************************************************************** ****************************************************************************** STATEMENT OF THE ISSUE: Some internal design model and signal names may exceed the current 20 character limit on the model_name and signal_name fields of [Model], particularly when the names are automatically generated. These must be truncated before their inclusion in an IBIS file. IBIS 4.1 extends maximum line lengths from 80 to 120 characters. With this change, model and signal names may safely be extended as well. This BIRD establishes a new limit of 40 characters on model and signal names. Note that the proposed change does not alter the five character maximum length of pin designators. Consequently, while [Series Pin Mapping] and [Model Selector] would be affected by this change, [Diff Pin] and [Pin Mapping] would not. ****************************************************************************** STATEMENT OF THE RESOLVED SPECIFICATIONS: Changes are noted in the relevant sections below by |* lines. Changes as the result of BIRD93.1 are noted by |**. In section 5, under [Pin], replace: | Column length limits are: | [Pin] 5 characters max | model_name 20 characters max | signal_name 20 characters max | R_pin 9 characters max | L_pin 9 characters max | C_pin 9 characters max with: | Column length limits are: | [Pin] 5 characters max |** signal_name 40 characters max |** model_name 40 characters max | R_pin 9 characters max | L_pin 9 characters max | C_pin 9 characters max Under [Series Pin Mapping], replace: | The column length limits are: | [Series Pin Mapping] 5 characters max | pin_2 5 characters max | model_name 20 characters max | function_table_group 20 characters max with: | The column length limits are: | [Series Pin Mapping] 5 characters max | pin_2 5 characters max |* model_name 40 characters max | function_table_group 20 characters max Under [Model Selector], replace: | Usage Rules: A programmable buffer must have an individual [Model] section | for each one of its modes used in the .ibs file. The names of | these [Model]s must be unique and can be listed under the | [Model Selector] keyword and/or pin list. The name of the | [Model Selector] keyword must match the corresponding model | name listed under the [Pin] or [Series Pin Mapping] keyword | and must not contain more than 20 characters. A .ibs file | must contain enough [Model Selector] keywords to cover all of | the model selector names specified under the [Pin] and [Series | Pin Mapping] keywords. | | The section under the [Model Selector] keyword must have two | fields. The two fields must be separated by at least one | white space. The first field lists the [Model] name (up to 20 | characters long). The second field contains a short | description of the [Model] shown in the first field. The | contents and format of this description is not standardized, | however it shall be limited in length so that none of the | descriptions exceed the 120-character length of the line that | it started on. The purpose of the descriptions is to aid the | user of the EDA tool in making intelligent buffer mode | selections and it can be used by the EDA tool in a user | interface dialog box as the basis of an interactive buffer | selection mechanism. with | Usage Rules: A programmable buffer must have an individual [Model] section | for each one of its modes used in the .ibs file. The names of | these [Model]s must be unique and can be listed under the | [Model Selector] keyword and/or pin list. The name of the | [Model Selector] keyword must match the corresponding model | name listed under the [Pin] or [Series Pin Mapping] keyword |* and must not contain more than 40 characters. A .ibs file | must contain enough [Model Selector] keywords to cover all of | the model selector names specified under the [Pin] and [Series | Pin Mapping] keywords. | | The section under the [Model Selector] keyword must have two | fields. The two fields must be separated by at least one |* white space. The first field lists the [Model] name (up to 40 | characters long). The second field contains a short | description of the [Model] shown in the first field. The | contents and format of this description is not standardized, | however it shall be limited in length so that none of the | descriptions exceed the 120-character length of the line that | it started on. The purpose of the descriptions is to aid the | user of the EDA tool in making intelligent buffer mode | selections and it can be used by the EDA tool in a user | interface dialog box as the basis of an interactive buffer | selection mechanism. In Section 6, under [Model], replace: | Usage Rules: Each model type must begin with the keyword [Model]. The | model name must match the one that is listed under a [Pin], | [Model Selector] or [Series Pin Mapping] keyword and must | not contain more than 20 characters. A .ibs file must | contain enough [Model] keywords to cover all of the model | names specified under the [Pin], [Model Selector] and [Series | Pin Mapping] keywords, except for those model names that use | reserved words (POWER, GND and NC). with: | Usage Rules: Each model type must begin with the keyword [Model]. The | model name must match the one that is listed under a [Pin], | [Model Selector] or [Series Pin Mapping] keyword and must |* not contain more than 40 characters. A .ibs file must | contain enough [Model] keywords to cover all of the model | names specified under the [Pin], [Model Selector] and [Series | Pin Mapping] keywords, except for those model names that use | reserved words (POWER, GND and NC). ****************************************************************************** ANALYSIS PATH/DATA THAT LED TO SPECIFICATION At least one semiconductor vendor has noted that its internal buffer naming convention exceeds the IBIS 20 character limit, which burdens model authors with manually shortening the names before adding them to the [Pin] list. A similar problem has been noted for pin signal names. The use of 40 characters for the model_name and signal_name fields came as the result of two assumptions: 1) That no specific new limit was desired; therefore a doubling of the existing limit was convenient 2) That the 120 character limit on line lengths in IBIS 4.1 and maintenance of pin names and pin RLC values at 5 and 9 characters respectively permitted at least 1 space between fields in the [Pin] keyword data set, with the signal_name and model_name extension (120 - 5 - 40 - 40 - 3*9 = 8 character spaces for separating 6 fields) For [Series Pin Mapping], the changes still permit a minimum of 16 spaces between fields (50 character spaces remain for separating 4 fields). Similarly, for [Model Selector], 80 character spaces remain available for use, divided between the comment field and white space, with the proposed changes. ***************************************************************************** ANY OTHER BACKGROUND INFORMATION: This issue has been separately raised by representatives of both EDA tool and semiconductor vendor companies. BIRD93.1 is issued to add an Analysis section and to change the [Pin] keyword line length limit statement to match the required column ordering. ******************************************************************************