2008-04-03 01:55:59     about PLL set

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2008-04-03 01:55:59     about PLL set

sj tian (CHINA)

Message: 53579   

 

When I control PLL under  visual  dsp++, I write code as following:

 

*pPLL_CTL = 0x3000;   //600M CCLK and 100M SLCK

*pPLL_DIV = 0x0006;

 

flags = cli();

idle();

 

sti(flags);

 

When under   uClinux, I used function below,

 

 

  bfin_write_PLL_CTL(0x3000);

  bfin_write_PLL_DIV(0x0006);

 

 

But I am not sure if I need added the following three sentences.  

  

   local_irq_save(flags);

   asm("IDLE;");

  local_irq_restore(flags);

 

If it have included set of idle mode in bfin_write_PLL_CTL( ) or bfin_write_PLL_DIV( ), .

 

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2008-04-03 02:24:29     Re: about PLL set

Yi Li (CHINA)

Message: 53581    there is some code examples in char/bfin_dpmc.c

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2008-04-03 09:24:17     Re: about PLL set

Mike Frysinger (UNITED STATES)

Message: 53602    you shouldnt need to program the PLL yourself ... u-boot/kernel takes care of it for you

 

as for the interrupt/idle sequence ... that is required as documented by the HRM.  the operating environment is irrelevant.

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