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questions about mcf52211's clock module

Question asked by Li Zhengping on May 25, 2009
Latest reply on May 25, 2009 by Mark Butcher

Hi all

I have some questions about mcf52211's clock module,hope you can geive me some explanations

1. the CLKMOD[1:0] Pins determine clock mode during POR, The 52211 reference manual says:

CLKMOD[1:0]    XTAL      Clocking Mode

00                    0           PLL disabled, clock driven by external oscillator

00                    1           PLL disabled, clock driven by on-chip oscillator

01                    N/A        PLL disabled, clock driven by external crystal

10                    0           PLL in normal mode, clock driven by external oscillator

10                    1           PLL in normal mode, clock driven by on-chip oscillator

11                    N/A        PLL in normal mode, clock driven by external crystal 

 my question is if I use MCF52211CAE66 (LQFP64 package), which has not CLKMOD1 pin, how about the clock mode during POR? for example if I connect CLKMOD0 pin to VCC33, what is the clock mode ?

 

2.The CCLR register select clock source, reference manual's table 6-11 says:

Table 6-11. CCLR[OSCSEL1] and CCLR[OSCSEL0] Settings

OSCSEL1 OSCSEL0         Source of PLL input/bypass clock

0            0                   Primary oscillator (default)

0            1                    Relaxation oscillator

1            0

                                  Secondary oscillator

1           1 

 my question is what is Primary oscillator and what is secondary oscillator?

 

thanks! 

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