Re: STM32F107 on STM3210C-EVAL

[jerzy dyrda <jerzdy@gmail.com>]

Hello all,

On Monday 28 March 2011 11:51:45 qber_@poczta.onet.pl wrote:
(...)
> There is only one thing left - the RCC differences. In RM there is a
> seperate section about RCC config for CL. But at the first look it seems
> that registers are compatible.
RCC registers are extended to support 2 extra PPL's with appropriate divider and multiplier.
Main differences is that source of PLL clock it isn't anymore taken directly from HSE or HSE/2 clock 
but it's introduced new divider PREDIV1 thus PLLSRC bit in RCC_CFGR register has partially 
different meaning. And another issue is external crystal. It value is 25MHz not 8 MHz like in 
STM3210E what causes need of using second PLL to produce CPU 72MHz.

HSE == 25MHz   /  PREDIV2 == 5 -> 5MHz   *  PLLMUL2 == 8 ->  
40MHz / PREDIV1 == 5 -> 8MHz * PLLMUL == 9 -> 72MHz = SYSCLK

It's looks ugly but above method it's used in ST source code for STM3210C evaluation board.

Best regards
jerzy