xmc4100 Clocks

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cross mob
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Hi,
The clock Details i found in In XMC4100 reference manual are as follows
External Clock: Which we will Connect to the Board and mine is 12Mhz
Slow Internal Clock: Fosi 32.768Khz.
My doubt is what is Fast Internal Clock: Fofi ??

i got only how to configure the Fofi i didn't find what is the Fast Internal Clock in Reference manual and Data Sheet??

Thanks And Regards,
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chismo
Employee
Employee
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Hello,

The Fofi is the back up clock source. Description from the reference manual (V1.5 2014-04, page 488) is as follows:

"The backup clock f_OFI generated internally is the default clock after start-up. It is used for
bypassing the PLL for startup of the system without external clock. Furthermore it can
be used as independent clock source for the watchdog module or even as system clock
source during normal operation. While in prescaler mode this clock is automatically used
as emergency clock if the external clock failure is detected."

Regards,
Min Wei
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Thanks for Reply,
Thanks for Useful Information i didn't find the back up clock frequency in XMC4100 reference manual. may i know how much frequency the Backup Internal Clock fofi is produced. like Fosi = 32.768KHz.
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chismo
Employee
Employee
First like received
This information can be found in the data sheet v1.2 2014-06, section 3.3.5 on Internal Clock Source Characteristics.

The Fofi is 36.5 MHz uncalibrated and 24 MHz calibrated.

Regards,
Min Wei
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Thank you very useful.
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