void SystemInit (void)
{
#if (CLOCK_SETUP) /* Clock Setup */
LPC_SC->SCS = SCS_Val;
if (SCS_Val & (1 << 5)) { /* If Main Oscillator is enabled */
while ((LPC_SC->SCS & (1<<6)) == 0);/* Wait for Oscillator to be ready */
}
LPC_SC->CCLKCFG = CCLKCFG_Val; /* Setup Clock Divider */
#if (PLL0_SETUP)
LPC_SC->CLKSRCSEL = CLKSRCSEL_Val; /* Select Clock Source for PLL0 */
LPC_SC->PLL0CFG = PLL0CFG_Val; /* configure PLL0 */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
LPC_SC->PLL0CON = 0x01; /* PLL0 Enable */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & (1<<26)));/* Wait for PLOCK0 */
LPC_SC->PLL0CON = 0x03; /* PLL0 Enable & Connect */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & ((1<<25) | (1<<24))));/* Wait for PLLC0_STAT & PLLE0_STAT */
#endif
#if (PLL1_SETUP)
LPC_SC->PLL1CFG = PLL1CFG_Val;
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
LPC_SC->PLL1CON = 0x01; /* PLL1 Enable */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & (1<<10)));/* Wait for PLOCK1 */
LPC_SC->PLL1CON = 0x03; /* PLL1 Enable & Connect */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & ((1<< 9) | (1<< 8))));/* Wait for PLLC1_STAT & PLLE1_STAT */
#else
LPC_SC->USBCLKCFG = USBCLKCFG_Val; /* Setup USB Clock Divider */
#endif
LPC_SC->PCLKSEL0 = PCLKSEL0_Val; /* Peripheral Clock Selection */
LPC_SC->PCLKSEL1 = PCLKSEL1_Val;
LPC_SC->PCONP = PCONP_Val; /* Power Control for Peripherals */
LPC_SC->CLKOUTCFG = CLKOUTCFG_Val; /* Clock Output Configuration */
#endif
#if (FLASH_SETUP == 1) /* Flash Accelerator Setup */
LPC_SC->FLASHCFG = FLASHCFG_Val;
#endif
}
谁能大体给讲解一下 |
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