Different crystal on USBizi and PLL configuration

NETMF & Gadgeteer
1

We are working on a project based on the USBizi chip and are using a Panda II as the prototyping platform.

Now that we are designing the custom board, it would be very convenient if we can place a 16MHz crystal we have used in other products. Since timings are very important in this project, I want to have it working at the original 72Mhz.

My concern is if there is time-critical stuff that will prevent the CLR from starting if the processor oscillator is off for a while.

So, my question is, will I be able to get to the stage of reconfiguring the PLL at the begginning of my .NET code and obtain the CPU rate of 72MHz?

I know I can get to the required registers from .NET (or even, if it proved more practical, from RLP, since the firmware already does some tasks at that level).

Thanks.

2

NETMF internally uses a static value for clock at compile time. Using different crystal requires a complete rebuild of the firmware. I suggest you stick with the default crystal.

3

Hmmm. Yeah, now that I think of it, even the bootloader could have problems if the USB block is working at an off-frequency at the beginning.

Well, it was worth clarifying. Thanks, anyway.