求助下面程序详细解释
void EnableAPLL( )
{
/* Enusre DPLL is running */
*( ioport volatile unsigned short* )0x1f00 = 4;
wait( 25 );
*( ioport volatile unsigned short* )0x1f00 = 0;
// MULITPLY
*( ioport volatile unsigned short* )0x1f00 = 0x3000;
// COUNT
*( ioport volatile unsigned short* )0x1f00 |= 0x4F8;
wait( 25 );
//*( ioport volatile unsigned short* )0x1f00 |= 0x800
// MODE
*( ioport volatile unsigned short* )0x1f00 |= 2;
wait( 30000 );
// APLL Select
*( ioport volatile unsigned short* )0x1e80 = 1;
// DELAY
wait( 60000 );
}
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楼主
