XPower Estimator (XPE) provides the following warning message:
Maximum startup current exceeds total estimated ICCINT.
What is the maximum startup current for the Spartan-6 LX16 and LX45 devices?
XPE reports that a total current on VCCINT of at least 0.4A is required during startup for the Spartan-6 XC6SLX16 -2C production device when calculated for maximum process. 0.48A is the current required on the VCCINT supply during startup for the Spartan-6 XC6SLX45 -2C production devices. This startup current is a temporary increase seen before the device begins configuration, and does not add to the operating current or have any other effect on operation. If this value exceeds the value calculated from the power estimators based on utilization and dynamic operating current, a warning message is shown that "Maximum startup current exceeds total estimated ICCINT." Other densities, speed grades, and operating conditions do not have this same requirement, and can have a much lower VCCINT total current requirement, especially for low-speed, low-utilization designs. NOTE: This additional startup current ONLY applies to initial production LX16 and LX45 devices. These devices are differentiated by their JTAG IDCODE "Version" value being less than 3. LX16 and LX45 Devices with JTAG IDCODE "Version" of 3 or more no longer have this additional startup current requirement, and therefore this warning does not apply. The startup current would be less than or equal to the device's normal static current as reported by XPE, even with no resources entered.
Use the Xilinx Power Estimator (XPE) tool to estimate maximum current requirements for your specific device and conditions.