Hi,
My goal is to use XPower to estimate the average and the peak power for a given run of a system with at least a reasonable level of accuracy.
Tools used are: Xilinx Platform Studio 6.2.03i Xilinx Project Navigator 6.2.03i ModelSim SE 5.7g
In order to test out the framework for evaluating power (Xpower), I have designed a Microblaze-based system with a C-application containing simple multiplication of two numbers. The whole system along with its simulation model was generated using XPS.
I am using the post-place&route simulation model to generate the VCD file. The system is triggered with its external inputs clk and rst (using a testbench.vhd) and simulation is run till the software (that was hard-coded in bram_init.vhd) produced the expected output. The commands used to add signals (before simulation) to VCD are as follows:
--------------------------- vcd file system.vcd vcd add testbench/uut/*
---------------------------
Then I tried running XPower with the generated VCD file with '-v -a' option. Some of the warnings reported were as follows: WARNING:Power:760 - Only 10% of the register output signals have been set. WARNING:Power:762 - Only 12% of the design signals have been set. WARNING:Power:763 - Only 6% of the design signals toggle. INFO:Power:556 - Estimate is inaccurate based on analysis of the design, user input and characterization data.
------------------------------------------------------------ XPower generated the power numbers but with an inaccurate confidence level.
Here are my questions:
(1) How to achieve a confidence level of at least "reasonable" if not "accurate"? Observation: A file called "systemfailed.txt" was also generated reporting "activity not set" error messages for a lot of signals. The error messages were like (Signal "opb_mdm_0/bscan_update" has not had its activity set.)
(2) The system clock frequency is 50 MHz. However, there were several warnings reported of the kind: "WARNING:Power:91 - Can't change frequency of net sys_clk to 5000.00Mhz." I don't know what to infer from there?
Please let me know if I am missing something while setting up the framework for running XPower.
Thanks and Regards, Partha.