s32k disabling the PLL

hajianik — Wed, 25 Nov 2020 22:00:07 GMT

Target is S32K144.

I'm trying to disable the SPLL,SOSC and FIRC clocks before entering VLPS mode

using the code snipt below will disable the last two but it fails to disable the SPLL.

Sorry it is a bit of mess.

2 different mask was used in the while loop:SPLLVLD bit which is commented out right now since I get stuck in it, The other one is LK bit that goes true but SPLLEN still remains 1.

SCG_RCCR = (uint32)((3 << 24)|(0 << 16)|(0 << 12)|(1 << 4)|(3 << 0));

SCG_SPLLCSR = (uint32)0x00; //&=~(1uL<<0);//(uint32)0x00; /* disable PLL */

while (SCG_SPLLCSR & 0x00800000UL /* 0x1000000*/){}; /* wait until PLL Lock is released */

SCG_SOSCCSR = (uint32)0x00; /* disable system OSC */

//SCG_RCCR = (uint32)((3 << 24)|(0 << 16)|(0 << 12)|(1 << 4)|(3 << 0));

SCG_FIRCCSR &= ~(1uL<<0); //disable FIRC

I NEED HELP RESOLVING THIS ISSUE.

Thanks,

Koorosh Hajiani

Re: s32k disabling the PLL

dianabatrlova — Thu, 26 Nov 2020 14:41:51 GMT

Hello,

At first, "When entering VLPR/VLPS mode, the system clock should be SIRC"

void init_SIRC(void)
{
SCG->SIRCCSR &= ~ (1 << 24);
// [24] LK = 0 Unlock Control Status Register

SCG->SIRCCSR |= 0x01;
// [2] SIRCLPEN = 0 Slow IRC is disabled in VLP modes
// [1] SIRCSTEN = 0 Slow IRC is disabled in Stop modes
// [0] SIRCEN = 1 Slow IRC is enabled

SCG->SIRCDIV |= 0x0404;
// [10-8] SIRCDIV2 0b100 Divide by 8 (1MHz)
// [2-0] SIRCDIV1 0b100 Divide by 8 (1MHz)

while((SCG->SIRCCSR & (1 << 24)) == 0); // wait until clock is valid
// [24] SIRCVLD = 1 Slow IRC is enabled and output clock is valid

SCG->SIRCCSR |= (1 << 24);
// [24] LK = 1 lock Control Status Register

}

void switch_to_SIRC_in_RUN(void)
{
uint32_t srie = RCM->SRIE;
RCM->SRIE = 0x0000; // configure all reset sources to be ‘Reset' (not as Interrupt)
RCM->SRIE = 0xFFFF; // Program each reset source as Interrupt via RCM_SRIE
// for a minimum delay time of 10 LPO.

SCG->RCCR = 0x02010013;
// [27-24] SCS = 2 Slow IRC (SIRC_CLK 8MHZ)
// [19-16] DIVCORE = 1 Divide by 2 (4 MHz)
// [7-4] DIVBUS = 1 Divide core by 2 (2 MHz)
// [3-1] DIVSLOW = 3 Divide core by 4 (1 MHz)

while(!((SCG->CSR & (0x0F000000)) & 0x02000000));
// [27-24] SCS = 0b0010 Slow IRC (SIRC_CLK)
// or
while((SCG->SIRCCSR & (1 << 25)) == 0);
// [25] SIRCCSR = 1 Until SIRC is the system clock source

RCM->SRIE = srie;
}

Then disable FIRC, SOSC, and SPLL

void disable_FIRC_SIRC_SOSC_in_RUN(void)
{
// When entering VLPR/VLPS mode, the system clock should be SIRC. The FIRC, SOSC,
// and SPLL must be disabled by software in RUN mode before making any mode
// transition.

if(!(SCG->SPLLCSR & (1 << 25)))
{
SCG->SPLLCSR &= ~(1 << 0);
while(SCG->SPLLCSR & (1 << 24));
}

if(!(SCG->FIRCCSR & (1 << 25)))
{ // [25] FIRCSEL, if FIRC is not the system clock source
SCG->FIRCCSR &= ~(1 << 0);
// [0] FIRCEN = 0 FIRC disabled
while(SCG->FIRCCSR & (1 << 24));
// [24] FIRCVLD = 0 Fast IRC is not enabled or clock is not valid
}

if(!(SCG->SOSCCSR & (1 << 25)))
{
SCG->SOSCCSR &= ~(1 << 0);
while(SCG->SOSCCSR & (1 << 24));
}

}

After that, all of them are disabled:

I hope it helps.

Best regads,

Diana

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Re: s32k disabling the PLL