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Altera_Forum
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11 years ago

Max5 Power Monitor

Hello, I'm working with the Arria starter kit. To start with, I've already seen this: http://www.alterawiki.com/wiki/how_to_read_power_monitor_value_in_system_console but I still have so...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Hi Jonah,

Yes, very likely it is "backwards" (i.e., the least significant byte is printed first).

I am sort of reverse engineering Power Monitor's behavior to automate some measurements on a Cyclone IV Development Kit.

Here are some observations, which may or not be true:

- The values read seem to the the least significant bits of a 24-bit ADC; in the formulas, some have advised dividing the reference voltage by 23 and multiplying by the value read.

- You can read the resistance values by looking at the components on the PCB, or by looking and the schematics or datasheets for your board.

- I believe all rails use the same reference voltage, because it is a single configuration for the whole ADC. In my board, it seems to be 5.37 or 5.0V.

- The number changing from 1 to 2 in your question# 3 is the value to be written in the instruction register. The second value should be a timeout in microseconds.

Hope this helps.

Ricardo