void rflpc_irq_init()
{
/* copy the interrupt vector */
int i;
for (i = 0 ; i < RFLPC_IRQn_COUNT ; ++i)
{
_ram_interrupts[i] = (rflpc_irq_handler_t) _rom_interrupts[i];
}
/* Set the VTOR register to remap the interrupt vector */
rflpc_irq_global_disable();
SCB->VTOR = (uint32_t) _ram_interrupts;
rflpc_irq_global_enable();
}
/* Initialise clock to use main oscillator for PLL0.
*/
void rflpc_clock_init(void)
{
/* Disable IRQs so that the FEED sequence of the PLL is atomic */
rflpc_irq_global_disable();
/* Lets follow the setup sequence p. 46 */
if (LPC_SC->PLL0STAT & (1<<24)) /* if PLL0 connected, disconnect */
{
/* Disconnect PLL0, set bit 1 to 0 */
LPC_SC->PLL0CON &= ~(1UL << 1);
/* send feed sequence to validate the disconnection */
RFLPC_PLL0_DO_FEED();
}
/* Disable PLL0, set bit 0 to 0 */
LPC_SC->PLL0CON &= ~(1UL);
/* feed sequence to validate disable */
RFLPC_PLL0_DO_FEED();
/* If we use the main oscillator */
#ifdef RFLPC_CLOCK_USE_MAIN_OSCILLATOR
/* Then, enable main oscillator and wait for it to be ready */
/* Select its range, if 1Mhz to 20Mhz, set 0 to bit 4 of SCS register
* otherwise, set to 1 (p. 28)*/
if (RFLPC_CLOCK_MAIN_OSCILLATOR_FREQUENCY >= 1000000 && RFLPC_CLOCK_MAIN_OSCILLATOR_FREQUENCY <= 20000000)
LPC_SC->SCS &= ~(1UL << 4);
else
LPC_SC->SCS |= 1UL << 4;
/* Enables it, set 1 to bit 5 */
LPC_SC->SCS |= (1UL << 5);
/* Wait for it to be stable by waiting a 1 on bit 6 */
while ((LPC_SC->SCS & (1UL << 6)) == 0);
/* Main oscillator is stable. Can now be used as source for PLL0 */
/* Select main oscillator as source for PLL0. Set bit 1:0 of CLKSRC register to 01 (p. 34) */
LPC_SC->CLKSRCSEL = ((LPC_SC->CLKSRCSEL & ~(3UL)) | 1);
#endif
/* Configure PLL0 with N= INPUT_DIVIDER and M=PLL_MULTIPLIER (p. 37) */
LPC_SC->PLL0CFG = (((RFLPC_CLOCK_INPUT_DIVIDER-1) << 16) | (RFLPC_CLOCK_PLL_MULTIPLIER-1));
/* validate the configuration */
RFLPC_PLL0_DO_FEED();
/* Enable PLL0 */
LPC_SC->PLL0CON |= (1UL);
RFLPC_PLL0_DO_FEED();
/* Set the CPU Clock divider (p. 55) */
LPC_SC->CCLKCFG = RFLPC_CLOCK_CPU_DIVIDER - 1; /* divide PLL0 output frequency */
/* Wait for PLL0 to lock desired frequency by monitoring bit 26 of register PLL0STAT (p. 39) */
while (! (LPC_SC->PLL0STAT & (1 << 26)));
/* Connect PLL0, set bit 1 to 1 */
LPC_SC->PLL0CON |= (1UL << 1);
/* validate connection */
RFLPC_PLL0_DO_FEED();
#ifdef RFLPC_CLOCK_USE_MAIN_OSCILLATOR
_rflpc_system_clock = (2*RFLPC_CLOCK_PLL_MULTIPLIER*(RFLPC_CLOCK_MAIN_OSCILLATOR_FREQUENCY/RFLPC_CLOCK_INPUT_DIVIDER))/RFLPC_CLOCK_CPU_DIVIDER;
#else
_rflpc_system_clock = (2*RFLPC_CLOCK_PLL_MULTIPLIER*(RFLPC_CLOCK_INTERNAL_OSCILLATOR_FREQUENCY/RFLPC_CLOCK_INPUT_DIVIDER))/RFLPC_CLOCK_CPU_DIVIDER;
#endif
/* Configure flash accelerator according to CPU clock (p. 70) */
if ( _rflpc_system_clock <= 20000000)
LPC_SC->FLASHCFG = 0x3A;
else if (_rflpc_system_clock <= 40000000)
LPC_SC->FLASHCFG = (1 << 12) | 0x3A;
else if (_rflpc_system_clock <= 60000000)
LPC_SC->FLASHCFG = (2 << 12) | 0x3A;
else if (_rflpc_system_clock <= 80000000)
LPC_SC->FLASHCFG = (3 << 12) | 0x3A;
else if (_rflpc_system_clock <= 100000000)
LPC_SC->FLASHCFG = (4 << 12) | 0x3A;
/* system is now working on PLL0 */
/* Enables the IRQs */
rflpc_irq_global_enable();
}