Clock speeds

geoff239955 · ‎2011-03-15

Posted on March 15, 2011 at 20:44

Clock speeds

Tesla DeLorean · ‎2011-05-17

Posted on May 17, 2011 at 14:28

In all likelyhood you are running the core at 12 MHz, your access to the GPIO pin transacts several buses and is not a good metric for CPU speed. If you want them to bang up and down rapidly use a timer output.

Want to measure the internal clocks, route them out the MCO pin.

Use the PLL set up to x6, and the core will run at 72 MHz.

Download the Dev/Eval version of Keil, and the ST firmware library. It's more productive than poking at a register level.

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geoff239955 · ‎2011-05-17

Posted on May 17, 2011 at 14:28

Hi Thanks for the quick reply. Yes I understand the test may not be a good one for speed checking and getting the hardware to turn a few tricks would be better. I need to get some info on the MCO pin!! And the clock config from what you are saying!! The Keil route would be a nice one but to much cash for the Eval stage for me. I guess they have a cut down version but I will grow to like it to much and then have to spend money, so I will for the time being stick with the renaissance ride tools. They are OK and free.