Stm32f103 HSE external clock and PLL question

[trisf]

Posted on September 14, 2012 at 07:26

Silly question

Can I use external clock source (RCC_CR HSEBYP=1, HSE=1 ) to drive PLL?

[Tesla DeLorean]

Posted on September 14, 2012 at 22:30

Can I use external clock source (RCC_CR HSEBYP=1, HSE=1 ) to drive PLL?

 

You should be able to, HSEBYP turns off OSC_OUT

The PLL should work fine with a 50/50 duty input at HSE/1 up to 8 MHz, it the duty is rougher consider HSE/2

You want to keep the PLL input in the 4-8 MHz range, so if your external clock is 8-16 MHz use HSE/2

[trisf]

Posted on September 18, 2012 at 06:54

Thank you Clive.