Capture to Allegro Interface

1
Capture to Allegro Interface

• Tim Brandis and Moji Friedholf

2
What is the Capture to Allegro interface?

• Before the 9.2.1 release, Capture used the third
  party interface to create a netlist, a unused pin
  list, and many device files.
• With the 9.2.1 release, Capture uses a modified
  version of the Concept netlister (called PXLLite)
  to produce three ASCII files.
• The new interface does not use device properties,
  instead all the part properties are placed into
  the PSTCHIP.DAT file.
• All of the net properties are included in the
  PSTXNET.DAT file.
• The PSTXPRT.DAT file (the expanded part list)
  lists each reference designator and the sections
  assigned to it.

3
CONFIGURATION FILE

• The configuration file specifies net, part
  (function), component instance and component
  definition properties. This mapping determines
  which properties may be netlisted from Capture to
  Allegro or back annotated from Allegro to
  Capture. If a Capture property is not included in
  the configuration file it is not passed to
  Allegro. Similarly, if an Allegro property is not
  listed in the file, it does not get back
  annotated to Capture.
• The configuration file is divided into four
  sections, written in a Windows .INI format.
• ComponentDefinitionProps Allegro component
  definition properties, output in PSTCHIP.DAT file
• ComponentInstanceProps Allegro component instance
  properties, output in PSTSPRT.DAT file
• netprops Allegro net properties, output in the
  PSTXNET.DAT file
• functionprops Allegro function properties, output
  in the PSTXPRT.DAT file
• You can have many different configuration files.
  All you need do is specify which file you want to
  use in the Setup dialog box.
• A list of typical properties used with Allegro
  may be found in the Capture-Allegro filter of the
  property editor. This filter is built on the
  PREFPROP.TXT file, which is copied to your
  Capture directory during installation.

4
Why did we make the change? What do we get with
the new interface?

• The third party interface gets the job done but
  the connection between the schematic and board
  file is tenuous at best. Back annotation was
  unstable and would often crash.
• The third part interface was quite lax in
  checking for correct properties and could create
  a netlist that would require a lot of work to
  bring into Allegro.
• The PXLLite interface allows Capture access to a
  robust back annotation process, design reuse
  modules (for 14.1), and constraint management
  (for 15.0).

5
What are the costs of the new interface?

• Tighter integration with Allegro requires that a
  lot more work occurs on the front end. In the old
  interface this work would be done at the Allegro
  end.
• Use of Concept style netlister requires the user
  to deal with legacy Concept/Allegro integration
  issues.
• The interface is still, in many ways, in its
  infancy. Issues are appearing as more an more
  customers create netlists from real world designs
• Our customers (and the support engineers) have to
  learn a new interface that has completely
  different requirements.

6
What are customers going to see that are familiar
with the old interface.

• Boards that use to work in 9.2 will likely be
  unable to run through the new interface without a
  number of errors.
• Engineers on the schematic side are going to be
  spending more time creating netlists since the
  interface is nitpicky.
• Engineers on the board side are going to be
  spending less time fixing problems with the
  netlists.
• If a customer has made significant investments in
  creating libraries to work with the third party
  interface are going to have to rework their
  libraries.

7
What are the major problems?

• DEVICE properties dealt with differently between
  the two interfaces. (Errors Alg0011, Alg0013,
  Alg0014, Alg0016)
• Parts with multiple power pins that have the same
  name are going to cause errors. (Errors Alg0045,
  Alg0050)
• Parts without pin numbers will cause errors.
  (Error Alg0031)

8
DEVICE properties

• Problem
• The third party interface all parts had to have a
  DEVICE property that would specify which device
  file the part information would end up in. In
  most cases all parts that shared the same PCB
  footprint would share the same DEVICE property.
• The PXLLite interface considers that all parts
  with the same DEVICE property are the same part.
• Consequence
• If a customer has setup a design for the third
  party interface and they netlist it in the
  PXLLite interface all parts that share the same
  device property but are not exactly the same will
  flag and error.
• Solution
• Remove the device properties from the design

9
Power pins with the same name

• Problem
• Concept requires that all power pins on a part
  have unique pin names.
• Consequence
• This was not a requirement in the old interface
  and has never been a requirement within Capture.
  Many parts in the Capture supplied libraries are
  actually build with multiple power pins that are
  the same name.
• Solution
• An ISR has been released that fixes this error.

10
Parts with no pin numbers

• Problem
• The PXLlite interface requires that all parts
  have pin name and pin numbers.
• Consequence
• This was not a requirement of the old interface
  and customers may have spent a lot of time
  creating libraries that will not work with the
  new interface. This is primarily a problem with
  two or three terminal devices.
• Solution
• Go into the library and add pin numbers to all
  pins on all parts.

11
Other issues that may come up

• Parts with conflicting value of Power Pin
  visible.
• Lower case reference designator names crash
  Allegro netin.
• Primitive names with trailing spaces
• Parts with no pins cause netlist error.
• Power pin visibility. (Error Alg0048)
• Invalid Characters. (Error Alg0037, Alg0038,
  ALG0051, Alg0052)
• All pins on the part are power pins. (Error
  Alg0053)
• No Connect pins (Error Alg0049)

12
Invalid Characters

• As per latest doc of ConceptHDL Library Reference
  Manual, the following are invalid character for
  pin names as well as net names in Flow PCRNUM
  403634
• 1. All Extended character set
• 2. /
• 3.
• 4. !
• 5. lt
• 6. gt
• 7.
• 8. \
• 9. "
• 10. ,
• Currently if we see Capture-Allegro flow few of
  these chars are valid too Ex lt, gt.
• Once if we start supporting Vector pins, lt and gt
  will become invalid chars in pin names.

13
When in doubt use the help

• The online help for this release is quite good.
  Reasonably clear descriptions and a number of
  good examples. Pretty much anything you might
  have a question about is covered in the manual.