Teensy 3.5 clock configuration

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wdekimpe

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Hi

For a new project I needed a small board with a cortexM4 controller, some IO and an SD card interface and USB.
The Teensy3.5 was just what I was looking for.
As the controller is from the same family as the one on the Freescale (NXP) FRDM-K64F developoment board, I though I would just go with the NXP MCUExpresso tools and use some examples there.

I also modified the Teensy board to be able to connect my Jlink debugger interface, which I have been using for all my projects lately.
So far I managed to get a USB CDC example project on the Teensy3.5, however, I still have a problem

When trying the clock configuration, the controller seems to get stuck.

Is there some example C- code for the clock configuration on the Teensy3.5 board?
I would like to be able to use the board at full speed - 120 MHz, and use the USB of course.
I tried several setups, for now I just take the default startup parameters (using the reset values) and my core clock is around 20 MHz I think. Any configuration of the clock seems to get me stuck.

Any ideas?
 
mmm, that seems a bit cryptic to me; and I am not mistaken, that is startup code for the MK20, not the MK64, so another version of Teensy?
 
that is why I wrote (sic!, means exactly so)
have a look into the code and you know why this is the right file.
 
@wdekimpe, if you have any doubt about what experienced senior members of these forums like WMXZ write, there is still the 1000+ pages reference manual for the MK64 processors. RTFM...
 
mmm, this is not going well, probably it is my wording which is upsetting:
i was not doubting what WMXZ wrote, I was just saying that i did not understand, as it was a bit too cryptic for me.

But hey, as I do not have a solution for my problem yet, I am reading the reference manual as you suggested.
I am just saying: I love the board, I have worked with Kinetis before, as well as with STM32, nRF51, SAM4 and other ARM controllers, but setting up my development environment is always a bit of a challenge the first few days, so I was just looking for some friendly support :)

I still do not get why my board does not start up - i am using the Kinetis SDK code, and seem to be stuck in a while loop waiting for the PLL to start up. Not sure why that is, probably high time to bring up the oscilloscope...

Anyway, I was not trying to be offensive, just looking for your advice..
 
Hi, just wanted to give an update on my progress to you friendly folks :)
After going through the manual on both the MCG and the oscillator, I got the clock configuration running.
I used the MCUXpresso configurator (https://mcuxpresso.nxp.com/en/clock) and I am using the SDK generated using the mcuxpresso SDK builder.

I got only one configuration wrong, namely the clock oscillator should be run in low power mode rather than high gain mode. After that, clock setup went pretty smoothly.
Now I am still struggling a bit with porting the SDHC and FATFS example from my FRDM-K64F to the Teensy 3.5, because I want to be able to read files on a mic but I'll get there as well I guess - got it working on the FRDM board pretty quickly.

Anyway, I hope it is useful for someone anyway...
 
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