annotate switching activity with TCF

Dear fellows,

 Please shine some light in how I should annotate switching activity properly.

I used "dumptcf -internal" to create a tcf file from my testbench simulation. I did not set any scope, so the tcf file annotates all of the switching activites of my DUT and of my testbench. Thats ok rite? I am assuming the RTL Compiler will ignore the switching activity recorded from my testbench and use only the numbers regarding the DUT instances. After I read the tcf file in RC and synthesize my DUT, I noticed that in the power report, some negative numbers came out.

Question1. Why does Cadence allow negative dynamic power in its report? Does it make sense?

Then, I generated tcf files using "dumptcf -internal -scope .." to each hierachical instance of my DUT. In RC, I performed multiple commands "read_tcf ...", but the numbers do not add to what the top-level scoped tcf file first gave me. The power analysis came out to be much lower even though I read the tcf files of each DUT instance.

Question2. Can i have RTL Compiler make multiple tcf reads? Does it override the previous read tcf?

Hope yall can help me! Sincerely,

Alex