- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I used power analyzer tool estimate a vcd fire, the result is nearly 67mw. Since I insert a resistor in the power supply rail of the FPGA core, and I measure that the current flow into the FPGA core is nearly 12mA. Because the power supply of the FPGA core is 1.2V in theory, so the measured power consumption is about 14.4mW when I run the test program (same with vcd file). My question is why the result get from the power analyzer tool is so larger than the result I measured? Thank you very much!
Link Copied
2 Replies
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Basically powerplay is using four items to come up with the number.
Toggle Rate, (typically defaults to 12.5%, but in your case you are using a VCD file). Temperature, (Takes worse case corner, normally hot.) Voltage Skew, (Probably takes worse case corner, high) Die Lot Skew (again takes worse case corner). All of these things have a significant effect on the total power of the device, and the worse case can have a significant impact on the power draw. The purpose of the tool is to give you a "Worse Case" design target. If you take your existing design, and increase the temperature to 70C you should see a significant difference in the current draw. The Die Skew is something that you won't be able to control, and your particular devices is probably not on the worse case corner, but is something you still need to take into account when designing your board.- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Thank you very much. I will have a look at it.
Reply
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page