DVT VHDL IDE User Guide
Rev. 24.1.5, 13 March 2024

23.1.8 Low Power Format Support

DVT analyzes power format files (either UPF or CPF) and presents power domain information in:

Power format project nature

In order to work with power format files, you have to enable the Power Format nature for your project.

  • In the New DVT Project Wizard check UPF/CPF

  • For an existing project, right-click on it in the Project Explorer View, choose Change DVT Nature then check UPF/CPF

The Power Format nature works only in conjunction with at least one of Verilog or VHDL natures.

Power format files

Use one of the following build configuration directives to specify a power format file to be analyzed:

Compatibility mode Directive
ANY+dvt_upf+<upf_file>


+dvt_cpf+<cpf_file>
ius.irun-lps_1801 <upf_file>


-lps_cpf <cpf_file>
vcs.vlogan


vcs.vhdlgan
-upf <upf_file>
questa.vlog


questa.vcom
-pa_upf <upf_file>

Power format analysis

At full build, after elaborating the design, DVT analyzes (interprets) the provided power format file and elaborates the power domains. TCL and power domain errors are detected and reported during this phase.

All analyzed power format files are decorated with a blue bullet. Files outside the project directory are automatically linked under the DVT Auto-Linked folder.

Implementation Note: By default, the working directory of the TCL interpreter is the DVT project directory. To change it, use +dvt_compilation_root within the invocation where the power format file is specified, for example:

+dvt_init
+dvt_compilation_root+/path/to/new/compilation/root
+dvt_upf /path/to/file.upf

Implementation Note: Environment variables defined using +dvt_setenv within the invocation where the power format file is specified are available in the TCL $::env array.

Tip: To print power format analysis debug information in the DVT Build Console add this directive to your build configuration file:

+dvt_pf_debug

Tip: If a file called dvt_pre_interpret.tcl exists in any of the the User and Common Settings Locations it will be interpreted before the provided power format file. If several such files exist, they will all be interpreted, in precedence order of the User and Common Settings Locations. This mechanism allows you to define TCL variables or functions for debugging or deployment purposes.

Incremental power format analysis

Whenever you change a power format file which was analyzed during the full build phase, DVT triggers a power format file analysis and a power domain elaboration.

Whenever you change a design file (Verilog or VHDL) which was compiled during the full build phase, DVT triggers a power domain elaboration (analysis of power format files is not performed).

The following Common Power Format (CPF) and Unified Power Format (UPF) commands are supported by DVT:

  • CPF up to Version 2.1

create_power_domain -name <power_domain_name> -default -instances <instance_list> -exclude_instances <instance_list>
set_hierarchy_separator <separator_character>
set_instance <instance>
include <cpf_file>

  • UPF (IEEE Std 1801™) up to Version 3.0

create_power_domain <power_domain_name> -elements <instance_list> -exclude_elements <instance_list> -include_scope -scope <scope>
upf_version <version>
set_scope <scope>
load_upf <upf_file> -scope <scope> -version <version>

23.1.8.1 Supply Network Diagram

The Supply Network Diagram shows all the power domains and power switches, and how they are connected via supply nets and ports.

To generate the Supply Network Diagram:

  • Click the Generate Diagram toolbar button and choose Supply Network Diagram

  • Right-click on the top instance of your design in the Design Hierarchy View and choose Show Supply Network Diagram

Tip: To visualize a power domain and all its connections, from the Schematic Diagrams, Flow Diagrams and Block Diagrams right click on an instance included in the extent of the power domain and choose Show in Supply Network Diagram.

Tip: To quickly jump from the Supply Network Diagram the control signal of a power switch, select the control port, right click and choose Go to Source.

Note: For readability, the path to control signals is shortened in the diagram labels. Select the control port to see its full path in the Inspect View.