Overview of dc_shell and dcnxt_shell

The Design Compiler tool offers command-line interfaces dcnxt_shell and dc_shell for synthesis and timing analysis, alongside the Design Vision GUI. Both are text-only environments where commands are entered at a prompt. DC Expert, a feature requiring a specific license, can be invoked using the dc_shell command in UNIX or Linux. To perform synthesis with DC Expert, use the compile command.

Here is a table summarizing the key points about dc_shell and dcnxt_shell:

Feature	dc_shell	dcnxt_shell
Interface Type	Command-line	Command-line
Environment	Text-only	Text-only
Purpose	Synthesis and Timing Analysis	Synthesis and Timing Analysis
Startup tasks	Creates a command log file. Reads and executes .synopsys_dc.setup files. Executes scripts specified with -f and -x. Displays header and prompt.	Creates a command log file. Reads and executes .synopsys_dc.setup files. Executes scripts specified with -f and -x. Displays header and prompt.
Command Entry	Interactive commands or Tcl scripts	Interactive commands or Tcl scripts
Command Language	Tcl with Design Compiler extensions	Tcl with Design Compiler extensions
Command Autocomplete	Available using Tab key	Available using Tab key
Command History	Available in GUI console	Available in GUI console
Output Redirection	Supported using > and >>	Supported using > and >>
Command Interruption	Supported using Ctrl+C	Supported using Ctrl+C
Log Files	ASCII and HTML (configurable)	ASCII and HTML (configurable)
Script Execution	Using dc_shell -f script_file_name or source script_file_name	Using dcnxt_shell -f script_file_name or source script_file_name
Help	help command for command list, command_name -help for options, man command_or_variable_name for manual pages	help command for command list, command_name -help for options, man command_or_variable_name for manual pages
License Viewing	Using commands or GUI	Using commands or GUI

Differences:

While the provided sources do not explicitly detail the differences between dc_shell and dcnxt_shell, some distinctions can be inferred:

• NDM Mode: dcnxt_shell supports NDM (New Data Model) mode, enabling the use of IC Compiler II reference libraries. The shell_is_in_ndm_mode command can check the current mode. dc_shell does not appear to support NDM mode.
• Fusion Libraries: dcnxt_shell supports the use of fusion libraries. The sources do not mention dc_shell in the context of fusion libraries.
• Command Availability: Some commands might be exclusive to one shell or have different behavior. For example, the source mentions that the dcnxt_use_icc2_link command is used in dcnxt_shell for specific IC Compiler II Link features.

Usage:

Both dc_shell and dcnxt_shell provide a powerful command-line environment for various synthesis tasks, including:

• Design Setup: Defining libraries, setting design environments, and specifying design constraints.
• Design Analysis and Optimization: Running compile commands, analyzing timing and power, and resolving design issues.
• Hierarchical Design: Working with hierarchical models, block abstractions, and top-level compile.
• DFT (Design for Test): Performing test-ready compile and generating test-related files.
• Physical Guidance: Using Synopsys Physical Guidance for improved correlation with physical implementation.
• Floorplan Exploration: Performing floorplan exploration with IC Compiler or IC Compiler II.

Note:

It's important to refer to the official Design Compiler documentation for the most up-to-date and complete information on the differences and usage of dc_shell and dcnxt_shell, as the provided source excerpts might not cover all aspects.