20.3.3 Advanced Analysis of I/Os

SmartPower provides an easy way of estimating the power consumption related to I/Os. You can then analyze power consumption in detail.

To display I/O power consumption:

  1. In the Summary tab, select By Type from the Breakdown drop-down list. The grid displays the total power consumption of all I/Os in the design, as well as all other components. If you use different I/O standards, and

    different Vcci power rails, you can also display the power consumption for each rail by selecting By Rail from the Breakdown drop-down list. Breakdown By Rail shows the power consumption and current for each Vcci rail in the design.

    1. In the Analysis tab, select the highest hierarchy level in the Hierarchy tree in the left pane. Select By Instance from the Breakdown drop-down list.
      1. In the Analysis tab, unselect all categories under Instances Contributions except I/Os, and then click Apply. The table then displays a list of all I/Os in the design, along with the power contribution of each individual I/O. The columns display important I/O attributes: external port name, load, standard, drive-strength, slew, and macro.
      2. In the Probabilities tab, you can control the output probability of each tri-state and bidirectional I/O. The probability is the percentage of time that the I/O is used as an output. The default value can be changed and a specific value can also be set for each bidirectional or tri-state I/O.