计算机科学论文代写 User Interfaces Ic Compiler

计算机科学论文代写 User Interfaces Ic Compiler

4.4.1 Setting Up the Libraries

IC Compiler requires both logic libraries and physical libraries. The following sections describe how to set up and validate these libraries.

• Setting Up the Logic Libraries:

IC Compiler uses logic libraries to provide timing and functionality information for all standard cells. In addition, logic libraries can provide timing information for hard macros, such as RAMs.

IC Compiler uses variables to define the logic library settings. In each session, you must define the values for the following variables (either interactively, in the .synopsys_dc.setup file, or by restoring the values saved in the Milkyway design library) so that IC Compiler can access the libraries:

• search_path

Lists the paths where IC Compiler can locate the logic libraries.

• target_library

Lists the logic libraries that IC Compiler can use to perform physical optimization.

• link_library

Lists the logic libraries that IC Compiler can search to resolve references.

• Setting Up the Physical Libraries:

IC Compiler uses Milkyway reference libraries and technology (.tf) files to provide physical library information. The Milkyway reference libraries contain physical information about the standard cells and macro cells in your technology library. In addition, these reference libraries define the placement unit tile. The technology files provide information such as the names and characteristics (physical and electrical) for each metal layer, which are technology-specific.

The physical library information is stored in the Milkyway design library. For each cell, the Milkyway design library contains several views of the cell, which are used for different physical design tasks.

If you have not already created a Milkyway library for your design (by using another tool that uses Milkyway), you need to create one by using the IC Compiler tool. If you already have a Milkyway design library, you must open it before working on your design.

This section describes how to perform the following tasks:

• Create a Milkyway design library

To create a Milkyway design library, use the create_mw_lib command (or choose File > Create Library in the GUI).

• Open a Milkyway design library

To open an existing Milkyway design library, use the open_mw_lib command (or choose File > Open Library in the GUI).

• Report on a Milkyway design library

To report on the reference libraries attached to the design library, use the -mw_reference_library option.

icc_shell>report_mw_lib-mw_reference_library\ design_library_name

To report on the units used in the design library, use the report_units command.

icc_shell> report_units

• Change the physical library information

To change the technology file, use the set_mw_technology_file command (or choose

File > Set Technology File in the GUI) to specify the new technology file name and the name of the design library.

• Save the physical library information

To save the technology or reference control information in a file for later use, use the

write_mw_lib_files command (or choose File > Export > Write Library File in the GUI). In a single invocation of the command, you can output only one type of file. To output both a technology file and a reference control file, you must run the command twice.

• Verifying Library Consistency:

Consistency between the logic library and the physical library is critical to achieving good results. Before you process your design, ensure that your libraries are consistent by running the check_library command. [16]

icc_shell> check_library

4.4.2 Setting Up the Power and Ground Nets

IC Compiler uses variables to define names for the power and ground nets. In each session, you must define the values for the following variables (either interactively or in the .synopsys_dc.setup file) so that IC Compiler can identify the power and ground nets:

• mw_logic0_net

By default, IC Compiler VSS as the ground net name. If you are using a different name,

you must specify the name by setting the mw_logic0_net variable.

• mw_logic1_net

By default, IC Compiler uses VDD as the power net name. If you are using a different name, you must specify the name by setting the mw_logic1_net variable.

4.4.3 Reading the Design

IC Compiler can read designs in either Milkyway or ASCII (Verilog, DEF, and SDC files) format.

• Reading a Design in Milkyway Format

• Reading a Design in ASCII Format