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rikka0w0 / STM8-VUSB

Low-speed USB implemented on STM8 microcontrollers
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Why we are using external clock of 12M instead of 15M internal clock? #1

Closed varunjithv closed 8 years ago

varunjithv commented 8 years ago

I would like to know why we are not able to use the internal clock for usb bit banging?

rikka0w0 commented 8 years ago

Well, the USB communication requires very precise timing. For a low speed USB device, the time interval of a bit mush be 2/3 us. If we use 12MHz crystal, 8 instruction cycles will be equal to that time. Other clock sources seems impossible to produce the required timing precision.

varunjithv commented 8 years ago

Thank you :+1:

rikka0w0 commented 8 years ago

Would you like to work together on this project?

varunjithv commented 8 years ago

Yes. Definitely. I am studying that project. Contact me on varunjithv@gmail.com!

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