CLKS: Fast setup of system clocks with PLL and dividers

The following example uses the IfxScuCcu_init function which allow us to set up to some pre-determine values the internal PLLs and peripheral divisor. We can also override the macro IFXSCU_CFG_CLK_DISTRIBUTION which in turn is a structure to set our own peripheral divisor values if we desire different frequencies. There are a set of functions belong to iLLD library allowing us to know which frequencies were set.

#include "Ifx_Types.h"
#include "IfxCpu.h"
#include "IfxScuWdt.h"
#include "Port/Io/IfxPort_Io.h"
#include "Scu/Std/IfxScuCcu.h"
#include "Bsp.h"
#include <stdio.h>

IFX_ALIGN(4) IfxCpu_syncEvent g_cpuSyncEvent = 0;

/*Array with default with preset values for PLL steps */
static IfxScuCcu_PllStepConfig IfxScuCcu_defaultPllConfigSteps[] = { IFXSCU_CFG_PLL_STEPS };
 /*presets wait state to configure the Flash memory*/
static const IfxScuCcu_FlashWaitstateConfig IfxScuCcu_defaultFlashWaitstateConfig = IFXSCU_CFG_FLASH_WAITSTATE;

/*Structure to configure the three internal PLL with the following frequencies
 * PLL0 = 300MHz, PLL1 = 320MHz and PLL2 = 160MHz */
IfxScuCcu_Config IfxScuCcu_testClockConfig = {
    IFXSCU_CFG_PLL_INITIAL_STEP,
    {
        sizeof(IfxScuCcu_defaultPllConfigSteps) / sizeof(IfxScuCcu_PllStepConfig),
        IfxScuCcu_defaultPllConfigSteps
    },
    IFXSCU_CFG_CLK_DISTRIBUTION,
    &IfxScuCcu_defaultFlashWaitstateConfig,
    &IfxScuCcu_defaultModConfig
};


void core0_main( void )
{
    volatile float32 AdcFreq;
    volatile float32 GtmFreq;
    volatile float32 CanFreq;
    volatile float32 SpiFreq;
    volatile float32 SysPllFrec, Per1PllFrec, Per2PllFrec, Cpu0Frec;

    IfxCpu_enableInterrupts();
    
    /* !!WATCHDOG0 AND SAFETY WATCHDOG ARE DISABLED HERE!!
     * Enable the watchdogs and service them periodically if it is required */
    IfxScuWdt_disableCpuWatchdog( IfxScuWdt_getCpuWatchdogPassword() );
    IfxScuWdt_disableSafetyWatchdog( IfxScuWdt_getSafetyWatchdogPassword() );
    
    /* Wait for CPU sync event */
    IfxCpu_emitEvent( &g_cpuSyncEvent );
    IfxCpu_waitEvent( &g_cpuSyncEvent, 1u );

    /* standard PLL & clock initialisation */
    IfxScuCcu_init( &IfxScuCcu_testClockConfig );

    /*REad some of the system and peripheral frequencies*/
    SysPllFrec = IfxScuCcu_getPllFrequency();
    Per1PllFrec = IfxScuCcu_getPerPllFrequency1();
    Per2PllFrec = IfxScuCcu_getPerPllFrequency2();
    Cpu0Frec = IfxScuCcu_getCpuFrequency( IfxCpu_ResourceCpu_0 );
    AdcFreq = IfxScuCcu_getAdcFrequency();
    GtmFreq = IfxScuCcu_getGtmFrequency();
    CanFreq = IfxScuCcu_getMcanFrequency();
    SpiFreq = IfxScuCcu_getQspiFrequency();

    while(1)
    {
        /*insert a break point right here and read the variables with the debugger*/
        waitTime( IfxStm_getTicksFromMilliseconds( BSP_DEFAULT_TIMER, 1000u ) );
    }
}