Startup power is the power required during the initial bring-up and configuration of the device. This power generally occurs over a very short period of time and thus is not a concern for thermal dissipation. However, current requirements must still be met. In most cases, the active current of an operating design will be higher and thus no changes are necessary. However, for lower-power designs where active current can be low, a higher current requirement during this time might be necessary. You can use the Xilinx Power Estimator (XPE) spreadsheet tool (download at www.xilinx.com/power) to understand this requirement. When Process is set to Maximum, the current requirement for each voltage rail is specified to either the operating current or the startup current, whichever is higher. XPE displays the current value in blue if the startup current is the higher value.