Цитата(Vladimir_T @ Aug 21 2009, 07:52)
Здравствуйте, уважаемые коллеги, в фойле .dsn для Specctra стоит командда:
resolution MIL 10000
Как она работает? Я правильно понимаю, что все разщения и контуры плейнов будут передаваться с этим разрешением?
А в правилах у меня все значения в мм. Specctra с какими единичами оперирует?
Specctra Design Language Reference (spdlr.pdf, стр.119):
The <resolution_descriptor> is used to map units for translation between the layout system and the tool, and has different meanings in the design file and the session file.
When a <resolution_descriptor> is not included in the design file, the default dimension unit is inch and the default resolution value is 2540000.
A <resolution_descriptor> should be included before the structure section in a design file. The <dimension_unit> value defines the dimensional units of the design and determines the internal representation of all dimensional numbers.
The implications of the <resolution_descriptor> are listed in the following example.
(pcb
(resolution mil 10)
(structure
(boundary (rect pcb 0 0 9000 4000))
. . .
)
)
The keyword mil within the resolution descriptor specifies the units for all dimensions in the design. It is the default unit unless overridden by a <unit_descriptor> elsewhere in the design file, such as within a library section.
In the previous example, the PCB boundary is 9000 mil by 4000 mil. The tool stores this as 90000 database units by 40000 database units. Notice that value 10 in the <resolution_descriptor> defines the internal resolution as 0.1 mil. This value (10) does not affect the unit of the dimensions supplied in the design.
If the smallest dimension in a design has four digits to the right of the decimal point (such as 0.0001), the <resolution_descriptor> must have at least five zeros as the least significant digits (such as 100000). Otherwise, a roundoff error can occur in representing the smallest
dimension. For example, a circle with a diameter of 4.2221 has a radius of 2.11105 and requires a fifth decimal place to avoid roundoff.
The combination of resolution and maximum PCB size must not exceed the value for an integer (231 or 2,147,483,648). For example, a resolution specification of resolution mm 100000 limits the maximum dimension to 21474 mm, or 21 meters. If the resolution used is
resolution mm 10000000, the maximum design size is only 214 mm, which is not large enough for most printed circuit boards.
When a <resolution_descriptor> is included in the session file, it describes how physical dimensions in real numbers are mapped to database units. If the previous example is in a session file rather than a design file, the <resolution_descriptor> maps database units to the units used in the host layout system. In this example, the translator writes a boundary of 900 mil by 400 mil into the layout system database.
У Кэйденса отличная документация. В ней написано всё, и даже более того. И главное с примерами.
Вопрос по Specctra
Aug 21 2009, 05:52
