MCF51AC128 MQX时钟设置函数

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 static void _mqx_clock_init_20MHz()      
{
    VMCF51AC_MCG_STRUCT_PTR mcg_ptr =
        (VMCF51AC_MCG_STRUCT_PTR)&(((VMCF51AC_STRUCT_PTR)BSP_IPSBAR)->MCG);
 
 
  /* Configure MCG to run in PEE Mode */
  /* 20MHz bus clock from a 4MHz external crystal */
 
  /* set up external oscillator */
  mcg_ptr->MCGC2 = 0x26; /* RANGE = 1; HGO = 0; ERCLKEN=1; EREFS = 1; BDIV = 00 (/1); */
  
  /* wait for oscillator to initialize - poll on OSCINIT bit of MCGSC*/
  while (!(mcg_ptr->MCGSC & 0x02)){}
 
  /* Configure MCGC3 to access the proper RDIV values */
  mcg_ptr->MCGC3 = 0x10; /* DIV32 = 1; */
   
  /* Select Clock Mode and Reference Divider */
  mcg_ptr->MCGC1 = 0x90; /* CLKS = 10; RDIV = 2 (/4, /128 with DIV32=1); IREFS = 0; */

  /* wait for Reference Status bit to update - poll on IREFST bit*/
  while (mcg_ptr->MCGSC & 0x10){}
 
  /* Wait for clock status bits to update */
  while (((mcg_ptr->MCGSC & 0x0C)>>2) != 0b10){}       
 
  /* Configure MCGC3 to select PLL and VDIV */
  mcg_ptr->MCGC3 = 0x5A; /* PLLS =1; DIV32 = 1; VDIV = 1010 (x40) */
 
   /* wait for PLL status bit to update - poll on PLLST bit*/
  while (!(mcg_ptr->MCGSC & 0x20)){}
 
   /* Wait for LOCK bit to set - poll on LOCK bit*/
  while (!(mcg_ptr->MCGSC & 0x40)){}   //调试时候程序一直执行这里

  /* Now running PBE Mode */
 
  /* Transition into PEE */
  mcg_ptr->MCGC1 = 0x10; /* CLKS = 00; RDIV = 2 (/4 with PLLS=1); IREFS = 0; */

  /* Wait for clock status bits to update */
  while (((mcg_ptr->MCGSC & 0x0C)>>2) != 0b11){};          

  /* Now running PEE Mode */

    return;
}
查询下MCGSC 的第6位作用是判断PLL与FLL是否锁定，mcg_ptr->MCGSC & 0x40)的含义应该是已经锁定了，难道是这个库写错了？？？有没有人遇到一样的问题

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