Cadence Foundation flow and db Tcl commands in Encounter

Cadence Foundation flow Cadence Foundation flow s(FF) are the recommended procedures for implementing flat, hierarchical, and low-power/CPF designs using the EDI system software FF provides a set scripts that gives an easy way to automate these flows The scripts generated from FF are a starting point for building an implementation environment, but we can customize the scripts at various points in the flow

Overview Specifying the flow to run Scripts for steps in the flow Subscripts Plug-in scripts

Overview Inputs for FF are setup.tcl edi_config.tcl lp_config.tcl The setup.tcl contains a single source of all design data required to run design The edi_config.tcl contains flow variables which can be used to customize the flow The lp_config.tcl file is used for low power designs

Using input files for FF, we can run Cadence genflow script to create the implementation environment with run scripts For any customization in the flow, edit setup.tcl, edi_config.tcl and lp_config.tcl

Specifying the flow to run The EDI system software selects the flow to run as follows If the vars(cpf_file) variable is defined, the low-power flow is run If the vars(partition_list) variable is defined, the hierarchical flow is run If neither of these flows is defined, the flat flow is run

Scripts for steps in the flow Each script runs independently, starting from the database created by the previous step and creating a database when it completes

Subscripts In addition to the setup.tcl script, the flow scripts use the following subscripts internally utils.tcl – common procedure for all foundation flows procs.tcl procedures that execute the EDI foundation flows

Plug-in scripts To customize the flow, plug-ins can be added into the flow These plug-ins lets us to include design- specific requirements while leaving the flow scripts unchanged Create a plug-in file in PLUG directory and place it in edi_config.tcl file

Db tcl commands EDI uses tcl shell for user command-line interface For each and every operation we do will have equivalent tcl command. This tcl command can be found in encounter.cmd file

Db commands Tcl commands in EDI are 3 types Pre defined commands with existing functionality Fe-tcl commands Db tcl commands

Pre-defined commands These pre-defined commands will have a defined functionality and can be found in EDI command reference These commands does a specific task as explained in the command reference e.g. placeDesign --- placed all instances Can be only used as the commands in tcl procedure script

Fe-tcl commands These fp-tcl commands are set of tcl procedures which can be used to query data inside EDI There are atleast around 3000 fp-tcl commands in EDI Very hard to remember Can be used to write our own tcl procedure scripts

Example fe tcl script proc user_get_all_ios { } { set ioList {} dbForEachCellFTerm [dbgTopCell] ftermId { set ioList [concat $ioList [dbFTermName $ftermId]] } return $ioList

Db-tcl commands New and very fast way of accessing the data from EDI No need to remember so many commands Very much helpful for tcl programming and automaton in EDI

To list all the attributes AND their values use a double question mark Using a single question mark will show you a list of the attributes available at this level. > dbGet head.? > head: allCells dbUnits layers mfgGrid objType props To list all the attributes AND their values use a double question mark Another starting point using dbget is ‘top’ Using top, we can access all design based info E.g. Examples using dbget >dbget head.layers.name >YM0 M1 M2 M3 M4 M5 M6 M7 M8 M9 CA V1 V2 V3 V4 V5 V6 V7 V8 OVERLAP >dbget top.name