What's New with DesignWare minPower Components
DesignWare® minPower Components extend the capabilities of DesignWare IP to reduce the power consumption of energy sensitive applications. This technology focuses on reducing power for datapath-intensive designs. DesignWare minPower Components, originally released in 2009.06-SP1, have undergone several updates over the last year. These updates have added features that help to provide better quality-of-results (QoR) and maximize the power savings achieved (Power QoR) with DesignWare minPower Components.
Incremental Datapath Gating: Before retiming, the enable signals of the first stage retiming registers that initially placed at the outputs are identified as DG enable signals. After retiming, the first stage registers can be moved into a gated DesignWare block. When this happens, the input signals are already held steady by its driver registers when the DG enable signal is off. Therefore, DG can reduce the power before retiming, but not after retiming. So the Incremental Datapath Gating feature has been added to enhance the datapath gating for retiming flows and improving Power QoR. Below are the commands to enable the incremental datapath gating feature:
set power_enable_datapath_gating true
#The next command is only needed in two pass retiming flows
#and should be called prior to the first compile
set_datapath_gating_options -retime <instance_name>
minPower Components Block-Level Control: This feature provides the ability to control minPower Components at the block level, allowing the flexibility to indicate where minPower Components should focus its efforts in a design. With this feature, you can maximize power savings by identifying the datapath blocks that consume the most power and enable minPower Components only to those blocks.
#This command enables/disables minPower optimizations globally
set_dp_smartgen_options -power_effort off
#This command enables/disables minPower optimizations per instance
set_dp_smartgen_options -power_effort auto <instance_name>
minPower Components Optimization in Leakage Mode: Prior to 2010.12-SP4, the minPower leakage optimizations were only enabled in leakage mode. In 2010.12-SP4 and onward all minPower Components optimization are used in leakage mode, providing savings of both dynamic and leakage power.
Datpath Content Report: command has been added to report the datapath content percentage in your design. Below is the command to generate the datapath content reporting:
This command reports the percentage of the design composed of singletons, extracted datapath content and total datapath. It also includes a breakdown of the types of operators and their bit widths. This information can be useful, since a design with more than 20% datapath content, having adders, multipliers, shifters, subtractors and large bit width operators (≥ 8 bit) is more likely to benefit from minPower Components.
DesignWare Datapath Power Report: A new report has been added to better understand the power contribution of each datapath cell towards total dynamic and leakage power and total power contribution from all datapath cells. This helps identify the datapath blocks that are big power contributors and what kind of savings to expect at top level based on the total power contribution from these blocks. This report also details available timing slack information for the datapath cells in the design.
set synlib_enable_analyze_dw_power true
minPower Components Optimization Reports: To better understand the power optimizations performed by minPower Components, new options have been added to report_resources command.
report_resources –hier -minpower –context
-minpower #report datapath blocks that are optimized for power
-context #reports switching information on inputs of all datapath blocks
With more blocks optimized for power and higher switching activity provided on inputs of datapath blocks, you can expect to see more power savings from minPower Components.
Enhanced DG Reporting to Better Understand Gating Opportunities: The gating report was enhanced so that it is easier for you to understand gating opportunities in your design. This report provides a datapath gating summary and gives reasons why operators are not gated (if any)
It is recommended you use 2010.12-SP5 or later DC versions to fully utilize all the latest features added to minPower Components.
New Instantiable minPower Components: DesignWare minPower Components also includes instantiable IP with low power features. Many of these components are related to DesignWare Building Block IP that perform the same function, but the minPower Components’ implementations apply low power strategies to save power, while providing the same functionality. The following describe some of the new instantiable components:
DW_lp_fp_multifunc_DG –Floating-Point version
Low power multifunctional math unit. Summary of features:
- Seven functions