$# CAMCAD - Professional Edition

· Allegro EDA PCB Reader

Cadence Allegro files have the default extension .brd. These binary files must be first "extracted" into ASCII files, before loading into CAMCAD. The extract is a program in the Allegro System and must be executed using the CAMCAD "valext.txt" file. The CAMCAD Allegro reader is user definable and adapts automatically to add-ons and changes in the extract file. However, the beginning records of the extract file must stay identically. The user can change the attribute section of the extract file.

"valout.txt" example as supplied with CAMCAD:

#

# VALID ALLEGRO OUTPUT SCRIPT FOR ROUTER SOLUTIONS SOFTWARE

#

# This Script creates 4 files : BRD.TXT PAD.TXT SYM.TXT RTE.TXT

#

# This is the new modified version May 92. (Router Solutions Inc.)

# This is the new modified version APR 94. (Router Solutions Inc.)

#Component values, partnumber and type was added.

#

# This is the new modified version MAY 94. (Router Solutions Inc.)

# Pin Rotation was added. This only work from

# Allegro version 6.

#

# This is the new modified version JUN 94. (Router Solutions Inc.)

# Test point was added.

#

# This is the new modified version DEC 96 (Router Solutions Inc.)

#User properties added.

# Board section was never used. Exchange it for Layer information

#BOARD

#BOARD_NAME

#BOARD_UNITS

#BOARD_EXTENTS_X1

#BOARD_EXTENTS_Y1

#BOARD_EXTENTS_X2

#BOARD_EXTENTS_Y2

#BOARD_LAYERS

#END

LAYER

LAYER_SORT

LAYER_SUBCLASS

LAYER_ARTWORK

LAYER_USE

LAYER_CONDUCTOR

LAYER_DIELECTRIC_CONSTANT

LAYER_ELECTRICAL_CONDUCTIVITY

LAYER_MATERIAL

LAYER_SHIELD_LAYER

LAYER_THERMAL_CONDUCTIVITY

LAYER_THICKNESS

END

PAD_DEF

END

GEOMETRY

# GENERATES PLACEMENT, SYMBOL, AND ETCH INFORMATION

SYM_TYPE

SYM_NAME

REFDES

SYM_X

SYM_Y

SYM_ROTATE

SYM_MIRROR

NET_NAME

CLASS

SUBCLASS

RECORD_TAG

GRAPHIC_DATA_NAME

GRAPHIC_DATA_NUMBER

GRAPHIC_DATA_1

GRAPHIC_DATA_2

GRAPHIC_DATA_3

GRAPHIC_DATA_4

GRAPHIC_DATA_5

GRAPHIC_DATA_6

GRAPHIC_DATA_7

GRAPHIC_DATA_8

GRAPHIC_DATA_9

GRAPHIC_DATA_10

COMP_DEVICE_TYPE

COMP_PACKAGE

COMP_PART_NUMBER

COMP_VALUE

# User Attributes are added here

BARCODE

BOARD_FIDUCIAL

BOARD_TOOLING

BREAKAWAY

CUTOUT

PANEL_FIDUCIAL

PANEL_TOOLING

ROBBER_BAR

CLIP_DRAWING

END

COMPOSITE_PAD

# GENERATES VIA AND NETLIST INFORMATION

# from here on down, these are user attributes and are optional

NET_NAME

PIN_NUMBER_SORT

CLASS

REFDES

SYM_TYPE

SYM_NAME

SYM_X

SYM_Y

SYM_ROTATE

SYM_MIRROR

PIN_NAME

PIN_NUMBER

PIN_X

PIN_Y

PAD_STACK_NAME

VIA_X

VIA_Y

# for Version 6

PIN_ROTATION

TEST_POINT

NET_PROBE_NUMBER

END

# End of VALOUT.SCR

================= end of example

Allegros extract program will return an error message, if you try to extract non-existant attributes.

How to run extract:

extract

<enter brd file name>: your_file_name

<enter .txt extract script> : valout.txt // will need 4 files, hit return on the fifth.

<enter filename> : brd.txt

<enter filename> : pad.txt

<enter filename> : sym.txt

<enter filename> : rte.txt

<enter filename> : <return>// no file name

Now the program will execute. Check extract.log for error messages.

The loading of the Allegro files can be in any order, or in simultanious selection.

.MIRRORLAYER in ALLEGRO.IN

In the extraced files, all components are exploded. This means every instance of a 1206 Resitor (R1,R2,R3) has its own library definition. CAMCAD rebuilds a library from the exploded data. Therefore the first instance of a shape becomes the master, from which all other instances are derived. To rebuild the mirrored shapes correctly, CAMCAD looks into the .MIRRORLAYER in the ALLEGRO.IN to "unmirror" layers.

File load sequence:

The 4 script files can be loaded in any sequence, however to correctly update BOARD_FIDUCIAL and PANEL_FIDUCIAL, it is important that the .s file (3rd file from extract) is loaded before the .r (4th file from extract). Only this guaranties that the FIDUCIAL of the pins are updated correctly with the symbol inserts.

SMD pad recognition:

A pad is flagged to be SMD if no drill diameter is set.

SMD component recognition:

SMD componenets are recognized like in CCMout. See SMD rule flag

in ALLEGRO.IN.

PADFORM SHAPE (complex outline) is read in as a Rectangle with X and Y size as defined in the extract file.