倍频要在程序里倍啊。。
// This function initializes the PLLCR register.
void Init_Pll(UINT val)
{
volatile Uint16 iVol;
PllVal = (val/2);
if (*SYSCTRL_REG_PLLCR != val)
{
EALLOW;
*SYSCTRL_REG_PLLCR = val;
EDIS;
// Optional: Wait for PLL to lock.
// During this time the CPU will switch to OSCCLK/2 until the PLL is
// stable. Once the PLL is stable the CPU will switch to the new PLL value.
//
// This switch time is 131072 CLKIN cycles as of Rev C silicon.
//
// Code is not required to sit and wait for the PLL to lock.
// However, if the code does anything that is timing critical,
// and requires the correct clock be locked, then it is best to
// wait until this switching has completed.
// If this function is run from waitstated memory, then the loop count can
// be reduced as long as the minimum switch time is still met.
// iVol is volatile so the compiler will not optimize this loop out
//
// The watchdog should be disabled before this loop, or fed within
// the loop.
DisableDog();
// Wait lock cycles.
// Note, This loop is tuned to 0-waitstate RAM memory. If this
// function is run from wait-stated memory such as Flash or XINTF,
// then the number of times through the loop can be reduced
// accordingly.
for(iVol= 0; iVol< ( (131072/2)/12 ); iVol++)
{
}
}
}
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楼主
