Automatic place and route with Cadence Encounter



analog-on-top (top level integration with Cadence IC, i.e. Virtuoso) vs digital-on-top (top level integration with Cadence Encounter) approaches

RTL-to-GDSII design flow

Encounter Digital Implementation System (EDI System)

Requirements: UNIX and TCL/Tk scripting.

Web tutorials

Reference documentation

  • Encounter Digital Implementation System User Guide

<install dir>/doc/soceUG/soceUG.pdf

  • Encounter Digital Implementation System Menu Reference

<install dir>/doc/encounter/encounter.pdf

  • Encounter Digital Implementation System Text Command Reference

<install dir>/doc/fetxtcmdref/fetxtcmdref.pdf

  • Encounter Digital Implementation System Foundation Flows Guide

<install dir>/doc/flowSetup/flowSetup.pdf

EDI System 11.x complete tutorial (from

If you have a Cadence Online Support account you can access a complete tutorial for Cadence EDI 11.x at the url;src=wp;q=Training/Digital_IC_Design/EDI11_Tutorial.html

All the necessary files (timing libraries, LEF files, captable files etc.) have been included in the tutorialDatabaseEDI11.tgz compressed archive.

See also here.

Getting started with Cadence Encounter

source /usr/local/config/cds_config/CdsEDI_912.rc

To start Cadence Encounter type

encounter [options]

at the command prompt. NO & !!!!


To quit the session use

encounter> exit

or go to File ⇒ Exit in the Cadence Encounter GUI.


encounter -help


encounter -version

View the log file:

encounter [-log /path/to/fileName]

Tools ⇒ Log Viewer… or

encounter> viewLog [-file /path/to/fileName]

This command opens the log file in a separate window. It opens the most recently created log file unless you specify a different log file with the -file parameter.

Help and documentation

You can run the Cadence Help which comes with the EDI installation,

/usr/cadence/EDI_9.12/tools/bin/cdnshelp &

or go to Help

encounter> help <command>


encounter> help viewLog

Usage: viewLog [-help] [-file <fileName>]

-help                # Prints out the command usage
-file <fileName>     # Data path group name (string, optional)

To see the complete set of information for an Encounter command, type the following command in the software console:

encounter> man <command>


encounter> man viewLog


To run Cadence Encounter you must first have physical libraries (cells and macros) defined in some technology file.

A technology file provides the software with design rules for placement and routing, and interconnect resistance and capacitance data for generating RC values and wireload models for the design. The technology file also contains process information for the metal interconnect layers, including metal thickness, metal resistance, and line-to-line capacitance values of metal layers, for determining coupling capacitance.


  • physical libraried definition file (e.g. .lef)
  • I/O assignment file
  • Timing libraries

To import LEF files in Encounter go to

File ⇒ Import Design

Advanced topics

  • technology file
  • LEF/DEF syntax references

Review of files

Encounter Foundation Flow (FF)

Generate Foundation Flow template:

encounter> writeFlowTemplate [-directory /path/to/template/directory]

or fron the Encounter GUI go through Flows ⇒ Generate Foundation Flow Template ⇒ Save

The above command makes a local copy of the

<install dir>/share/FoundationFlows/


Documentation: EDI System Foundation Flow User Guide (flowSetup.pdf)

<install dir>/doc/flowSetup/flowSetup.pdf


Design import

New 11.x release design import statements

encounter> set init_ [TAB]
init_abstract_view                init_io_file                      init_oa_search_lib
init_assign_buffer                init_layout_view                  init_oa_special_rule
init_cpf_file                     init_lef_file                     init_portable_path_vars
init_design_netlisttype           init_mmmc_file                    init_pwr_net
init_design_settop                init_oa_default_rule              init_top_cell
init_design_uniquify              init_oa_design_cell               init_verilog
init_gnd_net                      init_oa_design_lib
init_ignore_pgpin_polarity_check  init_oa_design_view
init_import_mode                  init_oa_ref_lib
encounter> init_design
encounter> help init_design
encounter> man init_design

MMMC view definition file

MMMC = Multi-Mode Multi-Corners

GUI ⇒ Import Design… and left click to Create Analysis Configuration File

Physical verification (Calibre)

You need to load Calibre interface in to EDI System

The procedure for installing this interface is contained in the Cadence Encounter section of Appendix A: Interfacing with Layout and Schematic Viewers of the Calibre Interactive User’s Manual (calbr_inter_user.pdf)

All necessary information can be found in

<install dir>/shared/pkgs/icv/tools/queryenc/

  • calencREADME README file
  • cal_enc.tcl main script
  • encounter.tcl
setenv CALIBRE_HOME /path/to/calibre/installation/directory
encounter> source /path/to/cal_enc.tcl


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