TECHNOLOGY FILE

Technology File is the most critical input for physical design tools. If you want to start any further steps or create a mw lib to start any further in physical design ? You must have tech file ready in your hand. Many companies start preparing their own tech file based on design rule runsets provided by foundry for that specific technology node or sometimes tech file comes as part of stdcell team.
In a nut shell : It provides technology-specific information like the names and physical and electrical characteristics of each metal/via layers and the routing design rules.
It guides physical design tool on below list of information:
  • Unit tile definitions that can be used in site rows so that placement engine can guide placement of cells ?
  • List of metals available for routing ?
  • Metal widths, spacing & pitch info etc.. ?
  • Design rules between same metal layer spacing ?
  • What are all the via types/via masters available ?
  • Units  of length, cap, power, resistance & technology precision etc.. ?
Not  only the listed factors above but tech file supports many other foundry guidelines and other useful physical design info. I would like give details by using a sample snippet of tech file below.
Details :
  • To write out the existing tech file from icc_shell : icc_shell> write_mw_lib_files -technology -output techfile.tf
  • File extension is ".tf" ; # not a hard rule :-)
  • A technology file consists of several sections, each of which uses the following syntax:
section_name {
    attribute_name = attribute_value…

}


I'm listing down some of the important sections of tech file.

Note :# There are many other sections in .tf . Depending on the complexity of fab rules and requirements, those extensive list can be used.If you have solvnet access , I would encourage you to read the following documents for detailed description.
There is lot of useful stuff at
 1) Synopsys Technology File and Routing Rules Reference Manual:
https://solvnet.synopsys.com/dow_retrieve/L-2016.09/iccolh/Default.htm#icctf/icctf.html 
3) 32nm and Below Design Rule Support in IC Compiler - Zroute:
https://solvnet.synopsys.com/retrieve/031863.html

* : The numbers below are random and does not convey any process specific. Just took for the sake of explaining..

Section 1 :
#----------------------------------------------------#
#Below section contains details of the technology : like name, units, precision of grid etc..
#----------------------------------------------------#
Technology {
    name                          =  "65nm"                 ; # name of the technology
    date                            =  "2016/10/22"        ; # date on when this file got updated ?
    dielectric                     =  <value?>                ; # value of di electric constant of this technology ?
    unitTimeName             =  "ps"                ; # time units : though units from .lib are used for timing analysis, we still need to keep here for consistency !!
    timePrecision               =  1000                ; # timing precision, you can go on till 100ps , later 1ns ?? details pls ?
    unitLengthName          =  "micron"                ; # physical dimension units
    lengthPrecision            =  1000                ; # precision of the physical drawn length ?
    unitVoltageName         = "V"                ; # voltage units : volts ==> V
    ….
    ….
    unitCapacitanceName             = "ff"                ; # capacitance units : femto farad
    capacitancePrecision            = 1000000                ; # details ??
   ....
   ….
}
Section 2:
#----------------------------------------------------#
# Declare all type colors you may use in the design, red, gree, blue etc..  (RGB)
# Once you go to metal layer definition section, you can assign these colors for metals using "color" options
#----------------------------------------------------#
Color 1 {
    name                            = "chocolate"
    rgbDefined                      = 1
    redIntensity                    = 100
    greenIntensity                  = 150
    blueIntensity                   = 200
}
Section 3:
#----------------------------------------------------#
# TILE definitions :# Most important info: unit tiles : based on these ICC site row definitions and std cell placement happen
# Can contain more than one type of tiles to accommodate diff scenarios
#----------------------------------------------------#
Tile "unit" {
    width                           = 0.5                 ; # min lego width  : X lego value
    height                          = 0.6                ; # min lego height : Y lego value
}
Tile "core" {
    width                           = 0.5                ; # same as above
    height                          = 0.6                ; # same as above;
    * we can various tile declarations as per need, while creating site rows, use corresponding tile definition
}
Section 4:
#----------------------------------------------------#
# Layer details:# details of layers : metal, via, diffusion , etc..: it contains : layer number , name , color, pattern, min width, pitch, etcc . drc wrto next metal/via */
#----------------------------------------------------#
Layer "m2" {                                        ;# layer details start: layer is m0
    layerNumber                     =  xx                  ;# layer number that will get shown on options while doing layout edits :
                                                    ;#  you can say stream compatible number which gets used for lvs reporting etc.. */
    maskName                         = "metal3"        ;# mask name , can be used for verify_lvs and also tech2itf comparisons. but m0 is the std names used for icc visual/internal routing
    isDefaultLayer                  = 1                ;# to denote if this is the default layer that ICC can use for physical implementation
    color                                = "red"        ;# what color do you want see this metal or layer ?
    pattern                             = "dot"        ;# what pattern : fill or dot or lines for this layer ?
    lineStyle                           = "solid"        ;# boundary line is solid ? or transparent etc..
    visible                              = 1                ;# is it a visible layer ?
    pitch                                =  1    ;# layer pitch, distance between center to center of m0 shapes that can be allowed
    minWidth                         =  0.5     ;# min width of the layer that can be drawn by ICC
    defaultWidth                     = 0.5      ;# what is the default width of the the layer ?
    minLength                       =  0.5      ;# how much is the min length of m0 can be drawn ?
    xMinSpacing                     = 0.5     ;# what is the min spacing in x direction that another m0 can sit ?
    yMinSpacing                     = 0.5     ;# what is the min spacing in y direction that another m0 can sit ?
    cornerMinSpacing              = 0.5     ;# m2 to m2 corner in another track allowed distance at min is ?
    minSpacing                       = 0.5     ;# details ?
     ..
    nonPreferredRouteMode           = 1        ;# to denote ICC whether m0 can be used for non - preferred direction routes if required ? 1 ==> no non-preferred routing, 0 : routing can be in any direction
    orthoSpacingExcludeCorner       = 1         ; # 1 means check only corner 2 corner space, not x and y as well
    onWireTrack                     = 1                ;# details ?
    yLegalWidthTblSize              = 4                ;# details ? : what can be the width of table
    yLegalWidthTbl                  = (0.5,0.6,0.7,0.8) ; # 0.046) * details ?
}
#----------------------------------------------------#
Layer "v2" {
    layerNumber                     =  xx
    maskName                       = "via2"
    isDefaultLayer                   = 1
    color                                 = "blue"
    pattern                             = "solid"
    minWidth                          = 0.5
    minSpacing                       = 0
    defaultWidth                     = 0.5
    maxStackLevel                  = 10
    onWireTrack                      = 1
    cutTblSize                           = 4
    cutNameTbl                   = (CUT1A, CUT1B,CUT1C,CUT1D)
    cutWidthTbl                   = (0.5,0.5,0.5,0.5)
    cutHeightTbl                   = (0.25,0.25,0.25,0.25)
    enclosedCutNumNeighbor          = 3 
    /* Enclosed cut rules */
    fatTblDimension             = 4
   /* list down all fatTbl related rules */
}
Section 5:
#----------------------------------------------------#
# Via Contact Codes# Via master properties like layers, resistance, enclosure etc..
#----------------------------------------------------#
ContactCode "VIA2AB" {
    contactCodeNumber               = 1
    cutLayer                        = "via2"
    lowerLayer                      = "m1"
    upperLayer                      = "m2"
    isDefaultContact                = 1
    cutWidth                        =  <value>
    cutHeight                       = <value>    
    upperLayerEncWidth             =  0.1
    upperLayerEncHeight            =  0.0
    lowerLayerEncWidth             =  0.1
    lowerLayerEncHeight            =  0.1
    minCutSpacing                     =  0.0
    unitMinResistance                 =  0.1
    unitNomResistance               =  0.1
    unitMaxResistance                =  0.1
}
Section 6:
#----------------------------------------------------#
#Via Cut Spacing Rules# list all DRs between tow cuts : within same layer or with adjacent layers (via set like v1-v1 and v1 <--> v2 etc..) that are used for ICC routing engine.
# general set of rules are : edge-edge, corner to corner and center to center of vias
#these rules can be between same net cuts (sameseg, samenet rules) or diff net cuts ( like if the cuts don’t share any immediate upper/lower metal - diffseg, diffnet rules
#As  of 2012, Synopsys ICC tech file was supporting 16 via cut rule types
#----------------------------------------------------#
DesignRule {
layer1 = "Via1"
layer2 = "Via2"
cut1TblSize = 4
cut2TblSize = 4
cut1NameTbl = (Vsm, Vv, Vh, Vlg)
cut2NameTbl = (Vsm, Vv, Vh, Vlg)
sameNetXMinSpacingTbl = (S11,S12,S13,S14,
  S21,S22,S23,S24,
  S31,S32,S33,S34,
  S41,S42,S43,S44)
diffNetXMinSpacingTbl = (D11,D12,D13,D14,
D21,D22,D23,D24,
D31,D32,D33,D34,
D41,D42,D43,D44)
}


All text between /* and */ is ignored.
Note :  orthoSpacingExcludeCornerTbl = (1) ; # specify this if both edge-edge and corner-corner rules are present and you want the tool to consider only corner-corner rules

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