GSCAN's SSN Scan File Contents

Introduction

The GSCAN program is a utility that supports many of Artwork's GDSII translators. This program scans through a GDSII file and extracts information about the structures, hierarchy, layers and datatypes containing actual data and extents of each structure.

A Simple SSN File

Below see a listing of a very simple SSN file generated from a die pad ring in GDSII format. It is simple because there is only one structure and two layers with data.Comments that are not part of the file are in italics.

FILENAME                   file name of scanned file goes here
FIRST_DIE.GDS

HEADER                      summary of GDSII header data 
Release           :3.00
Last Modify Time  :Sep 13, 10 at 10:30:20
Last Access Time  :Sep 13, 10 at 10:30:20
Resolution        :1000
User Units        :UM

Reference Library           if any reference libraries are listed
1)                          in the GDSII file they would appear here.
2)                          such info is not generally useful 

Text Font Definition Files  if a Calma font files was listed it would 
0)                          appear here. However it is not useful.
1) 
2) 
3) 


STRUCTURE_LIST              a list of all structure definitions in the file.
1) first_die                in order they are encountered 

LAYERS_CONTAINING_DATA      a list of layers that contain data.

0,1

DATATYPES_USED              a list of all datatypes encountered 

0

DATATYPES_PER_LAYER_USED    a list of specific layer:datatype combos 

0:0,1:0

STRUCTURE_ELEMENT_COUNTS (Boundary, Path, ARef, SRef, Text) 

1) first_die (337, 0, 0, 0, 0)     number of each type of element in this structure

STRUCTURE EXTENTS (Min X, Min Y, Max X, Max Y)   extents for each structure are
Resolution        :1000                          calculated.
User Units        :UM

1) first_die (-2100.000, -2100.000, 2100.000, 2100.000)

A More Complex SSN File

The above file had no "hierarchy to speak of -- all data was contained in a single top level structure. Now let's examine another relatively small SSN file that does have some hierarchy ... Comments are in italics and parts of the SSN file have been clipped for clarity.

FILENAME
TOP.DB

HEADER
Release           :3.00
Last Modify Time  :Jul 14, 87 at 0:00:00
Last Access Time  :Jul 14, 87 at 12:53:00
Resolution        :1000
User Units        :UM

Reference Library
1) REF:REFLIB1.DB
2) DZ1:REFLIB001.DB

Text Font Definition Files
0) BPD:FONT.TX
1) BPD:PGFONT0.TX
2) 
3) 


STRUCTURE_LIST    You can see that this file has 7 structures 
1) TOPMOSTST
2) PAD4MILS
3) TQE
4) PADCONT
5) SCNT
6) PLUG2
7) QE

LAYERS_CONTAINING_DATA

1,2,3,4,5,6,8,9,10,21,42

DATATYPES_USED

0,1,2,20,21

DATATYPES_PER_LAYER_USED

1:0,1:20,2:0,2:20,3:0,4:0,5:1,5:20,6:20,8:20,9:2,9:20,10:0,
10:20,21:21,42:20

STRUCTURE_ELEMENT_COUNTS (Boundary, Path, ARef, SRef, Text)

1) TOPMOSTST (55, 17, 0, 24, 6)
2) PAD4MILS (2, 0, 0, 0, 0)
3) TQE (5, 1, 0, 1, 0)
4) PADCONT (3, 0, 0, 0, 0)
5) SCNT (2, 0, 0, 0, 0)
6) PLUG2 (3, 0, 0, 0, 0)
7) QE (13, 0, 0, 0, 0)

STRUCTURE EXTENTS (Min X, Min Y, Max X, Max Y)
Resolution        :1000
User Units        :UM

1) TOPMOSTST (-18.500, 0.000, 249.000, 277.500)
2) PAD4MILS (0.000, 0.000, 99.000, 99.000)
3) TQE (-7.500, -7.500, 15.000, 7.500)
4) PADCONT (-2.000, -2.000, 17.000, 17.000)
5) SCNT (-1.500, -1.500, 1.500, 1.500)
6) PLUG2 (0.000, -1.500, 19.500, 13.500)
7) QE (-7.500, -7.500, 12.000, 7.500)

HIERARCHY of INDEPENDENT STRUCTURES    this section shows the hierarchy of
                                          GDSII file.


TOPMOSTST
  |
  |__ PAD4MILS
  |
  |__ TQE
  |     |
  |     |__ QE
  |
  |__ PADCONT
  |
  |__ SCNT
  |
  |__ PLUG2