Synopsys Design Constraints

Synopsys Design Constraints

 Synopsys Design Constraints is TCL-based format. All commands in an SDC file  follow the tcl syntax rules.

Third-party EDI tools are supported the SDC format. These files are generated by either manually or third party tools. These files are generated by the Design Compiler and Prime Time tools. 

It contains the following information:

• SDC version 
• Design Constraints 
• Comments ( optional )  

Specifying SDC version:

sdc_version variable specifies the version of the sdc file. 

To specify the sdc version , set this variable in the SDC file:

          set sdc_version value

Ex:

            set sdc_version 1.9

Design Constraints:

     Design Constraints are specified with help of the synopsys constraints commands. The SDC format consists of  the Synopsys Commands list shown in below.

• Design Objects :

                           Most of the constraint commands require a design object as a command argument.. It supports both implicit and explicit object specification.

                          For example,  if you have a cell in the current instance named U1,

                                                 the implicit specification is U1 , the explicit specification is  [get_cells U1]

Design objects supported by the SDC format as shown in the below: