lemcu / LemcUSB

A purely software based USB peripheral for ARM Cortex M0+ devices
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Could LemcUSB run on a Silicon Labs EFR32MG21? #3

Open ewheelerinc opened 3 years ago

ewheelerinc commented 3 years ago

We are using a Silicon Labs EFR32MG21 which is an ARM Cortex-M33 at (up to) 80MHz.

The EFR32xG21 WSTK dev board comes with a 38.4MHz external crystal, and in fact the datasheet says "any crystal frequency other than 38.4 is expressly not supported."

Since your chip and the one we are developing for are both Silicon Labs parts, I'm guessing that porting is somewhat simple, but what about clocking? Is the 24MHz clock a critical frequency to run the software USB implementation?

Other considerations?

Thank you for your help!

-Eric