1、 GEIA STANDARD I/O Buffer Information Specification (IBIS) Version 4.2 EIA-STD-656-B September 2006 GOVERNMENT ELECTRONICS AND INFORMATION TECHNOLOGY ASSOCIATION EIA-STD-656-B A Sector of the Electronic Industries Alliance ANSI/EIA-STD-656-B Approved: March 1, 2007 Copyright Government Electronics ?
2、 | | | Other Notes: The Comment Char keyword can be used anywhere in the file, | as desired. |- Comment Char |_char | |= | Keyword: File Name | Required: Yes | Description: Specifies the name of the IBIS file. | Usage Rules: The file name must conform to the rules in paragraph 3 of | Section 3, GENE
3、RAL SYNTAX RULES AND GUIDELINES. In addition, | the file name must use the extension “.ibs“, “.pkg“, or | or “.ebd“. The file name must be the actual name of the file. |- File Name ver4_1.ibs | |= Copyright Government Electronics the pullup_ref column in this case | must contain the reserved word NC
4、. Similarly, for POWER | (including external reference) pins, the pullup_ref column | contains the name of the bus to which the pin connects; the | pulldown_ref column in this case must contain the reserved | word NC. | | If the Pin Mapping keyword is present, then the bus | connections for EVERY pi
5、n listed under the Pin keyword must | be given. | | If a pin has no connection, then both the pulldown_ref and | pullup_ref subparameters for it will be NC. | Copyright Government Electronics two use 7 SPECIAL3 ref_buffer2 | external reference voltages 11 VSS1 GND 12 VSS1 GND 13 VSS1 GND 21 VSS2 GND
6、 22 VSS2 GND 23 VSS2 GND 31 VCC1 POWER 32 VCC1 POWER 33 VCC1 POWER 41 VCC2 POWER 42 VCC2 POWER 43 VCC2 POWER 51 VSSCLAMP GND | Power connections for clamps 52 VCCCLAMP POWER | 71 V_EXTREF1 POWER | External reference voltage pins 72 V_EXTREF2 POWER | | |= | Keyword: Diff Pin | Required: No | Descript
7、ion: Associates differential pins and defines their differential | receiver threshold voltage and differential driver timing | delays. | Sub-Params: inv_pin, vdiff, tdelay_typ, tdelay_min, tdelay_max | Usage Rules: Enter only differential pin pairs. The first column, Diff | Pin, contains a non-inver
8、ting pin name. The second column, | inv_pin, contains the corresponding inverting pin name for | I/O output. Each pin name must match the pin names declared | previously in the Pin section of the IBIS file. The third | column, vdiff, contains the specified differential receiver | threshold voltage b
9、etween the inverting and non-inverting | pins for Input or I/O model types. The fourth, fifth, and | sixth columns, tdelay_typ, tdelay_min, and tdelay_max, | contain launch delays of the non-inverting pins relative to | the inverting pins. All of the numerical entries may be a | positive, zero, or n
10、egative number. | | For differential Input or I/O model types, the differential | input threshold (vdiff) overrides and supersedes the need | for Vinh and Vinl. | | Other Notes: The output pin polarity specification in the table overrides | the Model Polarity specification such that the pin in the |
11、 Diff Pin column is Non-Inverting and the pin in the inv_pin | column is Inverting. This convention enables one Model to | be used for both pins. Copyright Government Electronics and tdelay_max column, | maximum magnitudes. One entry of vdiff, regardless of its | polarity, is used for difference mag
12、nitudes. | | The positioning of numerical entries and/or “NA“ must not be | used as an indication for the model type. The model type is | determined by the model type parameter inside the Models | referenced by the Diff Pin keyword, regardless of what the | Diff Pins entries are. The simulator may i
13、gnore the | vdiff or the tdelay_* parameters if not needed by the | model type of the Model, or use the default values defined | above if they are needed but not provided in the Diff Pin | keyword. For example, an “NA“ in the third column (vdiff) | does not imply that the model type is Output, or th
14、ree | “NA“-s in the tdelay columns does not mean that the model | type is Input. | | Note that the starting point of the flight time measurements | will occur when the differential drivers output waveforms | are crossing, i.e. when the differential output voltage is | zero, and consequently Vmeas, i
15、f defined will be ignored. |- Copyright Government Electronics & Information Technology Association Provided by IHS under license with GEIA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-EIA-STD-656-B 22 Diff Pin inv_pin vdiff tdelay_typ tdelay_min tdelay_max | 3
16、4 150mV -1ns 0ns -2ns | For Input, tdelay_typ/min/max ignored | For Output, vdiff ignored | 7 8 0V 1ns NA NA 16 15 200mV 1ns | For Input, tdelay_typ ignored | For Output, vdiff ignored and tdelay_min = 0ns and tdelay_max = 1ns | For I/O, tdelay_min = 0ns and tdelay_max = 1ns | 9 10 NA NA NA NA 22 21
17、 NA NA | For Input, vdiff = 200 mV | For Output, tdelay_typ/min/max = 0ns | For I/O, vdiff = 200 mV and tdelay_typ/min/max = 0ns | 20 19 0V NA | For Output, vdiff ignored and tdelay_typ/min/max = 0ns | For I/O, tdelay_typ/min/max = 0ns | |= | Keyword: Series Pin Mapping | Required: No | Description:
18、 Used to associate two pins joined by a series model. | Sub-Params: pin_2, model_name, function_table_group | Usage Rules: Enter only series pin pairs. The first column, Series Pin | Mapping, contains the series pin for which input impedances | are measured. The second column, pin_2, contains the ot
19、her | connection of the series model. Each pin must match the pin | names declared previously in the Pin section of the IBIS | file. The third column, model_name, associates models of | type Series or Series_switch, or model selectors containing | references to models of type Series or Series_switch
20、 for | the pair of pins in the first two columns. Each model_name | must have a corresponding model or model selector name | listed in a Model or Model Selector keyword below. The | usage of reserved model names (POWER, GND, or NC) within the | Series Pin Mapping keyword is not allowed. The fourth |
21、 column, function_table_group, contains an alphanumeric | designator string to associate those sets of Series_switch | pins that are switched together. | | Each line must contain either three or four columns. When | using four columns, the header function_table_group must be | listed. | | One possib
22、le application is to model crossbar switches where | the straight through On paths are indicated by one | designator and the cross over On paths are indicated by | another designator. If the model referenced is a Series | model, then the function_table_group entry is omitted. | Copyright Government Electronics & Information Technology Association Provided by IHS under license with GEIA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-
