void SYS_CLK_Initialize( const SYS_CLK_INIT const * clkInit )
{
SYS_DEVCON_SystemUnlock ( );
PLIB_OSC_FRCDivisorSelect( OSC_ID_0, OSC_FRC_DIV_2);
/* Enable Peripheral Bus 1 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 0, 1 );
/* Disable REFCLKO1*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, 0 );
/* Disable REFCLK1_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, 0 );
/* Disable REFCLKO2*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, 1 );
/* Disable REFCLK2_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, 1 );
/* Disable REFCLKO3*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, 2 );
/* Disable REFCLK3_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, 2 );
/* Disable REFCLKO4*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, 3 );
/* Disable REFCLK4_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, 3 );
SYS_DEVCON_SystemLock ( );
}
void SYS_CLK_Initialize( const SYS_CLK_INIT const * clkInit )
{
SYS_DEVCON_SystemUnlock ( );
PLIB_OSC_FRCDivisorSelect( OSC_ID_0, OSC_FRC_DIV_1);
/* Enable Peripheral Bus 1 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 0, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 0 );
/* Enable Peripheral Bus 2 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 1, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 1 );
/* Enable Peripheral Bus 3 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 2, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 2 );
/* Enable Peripheral Bus 4 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 3, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 3 );
/* Enable Peripheral Bus 5 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 4, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 4 );
/* Enable Peripheral Bus 7 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 6, 1 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 6 );
/* Enable Peripheral Bus 8 */
PLIB_OSC_PBClockDivisorSet (OSC_ID_0, 7, 2 );
PLIB_OSC_PBOutputClockEnable (OSC_ID_0, 7 );
/* Disable REFCLKO1*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, OSC_REFERENCE_1 );
/* Disable REFCLK1_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, OSC_REFERENCE_1 );
/* Disable REFCLKO2*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, OSC_REFERENCE_2 );
/* Disable REFCLK2_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, OSC_REFERENCE_2 );
/* Disable REFCLKO3*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, OSC_REFERENCE_3 );
/* Disable REFCLK3_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, OSC_REFERENCE_3 );
/* Disable REFCLKO4*/
PLIB_OSC_ReferenceOscDisable ( OSC_ID_0, OSC_REFERENCE_4 );
/* Disable REFCLK4_OE*/
PLIB_OSC_ReferenceOutputDisable ( OSC_ID_0, OSC_REFERENCE_4 );
SYS_DEVCON_SystemLock ( );
}
bool _SYS_CLK_ReferenceFrequencySet ( CLK_BUSES_REFERENCE referenceBus, CLK_SOURCES_REFERENCE referenceSource,
uint32_t targetFreqHz, bool waitUntilComplete, uint32_t *clockClosest )
{
unsigned long inputFreq = 0, tempFreq = 0;
uint32_t pllMult = 0, pllIDiv = 0;
double number = 0.f;
unsigned long ipart_number = 0;
double fpart_number = 0.f;
unsigned long divisor = 0;
float trimValue = 0.f;
const long scale = 100;
CLK_SOURCES_SYSTEM systemSource;
if (referenceBus != CLK_BUS_REFERENCE_1)
return false;
switch ( referenceSource )
{
case CLK_SOURCE_REF_SYSTEMCLK:
/* The clock source is System clock itself */
inputFreq = clkObject.systemClock;
break;
case CLK_SOURCE_REF_PBCLK_BUS1:
/* The clock source is Peripheral clock */
inputFreq = clkObject.peripheralClock[referenceBus];
break;
case CLK_SOURCE_REF_PRIMARY:
/* If the System clock is directly using the from the Primary oscillator
clock, return the configured primary oscillator frequency */
inputFreq = SYS_CLK_CONFIG_PRIMARY_XTAL;
break;
case CLK_SOURCE_REF_FRC:
/* Source of system clock is internal fast RC. If the System clock
is directly using the fast RC clock, return the Fast RC clock */
inputFreq = SYS_CLK_FRC_CLOCK;
break;
case CLK_SOURCE_REF_LPRC:
/* Processor's internal LPRC clock */
inputFreq = SYS_CLK_LPRC_CLOCK;
break;
case CLK_SOURCE_REF_SECONDARY:
inputFreq = SYS_CLK_CONFIG_SECONDARY_XTAL;
break;
case CLK_SOURCE_REF_USBPLL_OUT:
/* Find the closest register value in the hardware */
/* USBPLL_OUT is not directly an input to REFCLOCK. The USBPLL_OUT
* is given to REFCLOCK before the SYS_CLK_CONFIG_USBPLL_DIVISOR
* (value 2) is applied. */
inputFreq = SYS_CLK_UPLL_BEFORE_DIV2_FREQ;
break;
case CLK_SOURCE_REF_SYSPLL_OUT:
/* Source of system clock is SPLL with divisors */
pllMult = _SYS_CLK_PLLMultiplierRead();
pllIDiv = _SYS_CLK_PLLInputDividerRead();
/* Read the current system clock source from the register */
systemSource = PLIB_OSC_CurrentSysClockGet ( OSC_PLIB_ID );
if (systemSource == SYS_CLK_SOURCE_PRIMARY_SYSPLL)
{
inputFreq = ( SYS_CLK_CONFIG_PRIMARY_XTAL * pllMult ) / pllIDiv;
}
else if (systemSource == SYS_CLK_SOURCE_FRC_SYSPLL)
{
inputFreq = ( SYS_CLK_FRC_CLOCK * pllMult ) / pllIDiv;
}
else
{
inputFreq = 0;
}
break;
case CLK_SOURCE_REF_EXTERNAL:
/* Source of system clock is internal fast RC with PLL.
Find the closest register value in the hardware */
inputFreq = SYS_CLK_CONFIG_EXTERNAL_CLOCK;
break;
default:
break;
}
/* Failure case if the input is not supported */
if (inputFreq == 0)
{
*clockClosest = 0;
clkObject.systemClockStatus = SYS_CLK_OPERATION_FAIL_NOT_ACHIEVABLE;
return false;
}
/* Find the divisor value, find the equation in the datasheet */
number = inputFreq / ( targetFreqHz * 2.0 );
ipart_number = (unsigned long) number;
divisor = ipart_number;
fpart_number = number - ipart_number;
/* Check whether the divisor is within limit */
if ( ( divisor > 0 ) && ( divisor <= CLK_REFERENCE_DIVISOR_MAX ) )
{
//Blocking implementation
while(waitUntilComplete && PLIB_OSC_ReferenceOscSourceChangeIsActive ( OSC_PLIB_ID, referenceBus ))
{
PLIB_OSC_ReferenceOscDisable( OSC_PLIB_ID, referenceBus );
continue;
}
trimValue = fpart_number*512;
if (trimValue > CLK_REFERENCE_TRIM_MAX)
{
trimValue = CLK_REFERENCE_TRIM_MAX;
}
else if (trimValue < 0)
{
//We really should not have -ive trim value
trimValue = 0;
}
if ( !PLIB_OSC_ReferenceOscSourceChangeIsActive ( OSC_PLIB_ID, referenceBus ) )
{
/* Unlock before you switch */
SYS_DEVCON_SystemUnlock ( );
/* Switch the Reference clock source */
PLIB_OSC_ReferenceOscBaseClockSelect ( OSC_PLIB_ID,
CLK_BUS_REFERENCE_1, referenceSource );
PLIB_OSC_ReferenceOscDivisorValueSet ( OSC_PLIB_ID, referenceBus, divisor );
PLIB_OSC_ReferenceOscTrimSet ( OSC_PLIB_ID, referenceBus, trimValue );
PLIB_OSC_ReferenceOscEnable ( OSC_PLIB_ID, referenceBus );
PLIB_OSC_ReferenceOutputEnable ( OSC_PLIB_ID, referenceBus );
/* Lock it back right after completing all the register related operations */
SYS_DEVCON_SystemLock ( );
tempFreq = inputFreq / ( 2 * ( divisor * scale + ( trimValue * scale / 512 ) ) ) ;
*clockClosest = tempFreq * scale;
}
else
{
*clockClosest = 0;
clkObject.systemClockStatus =
SYS_CLK_OPERATION_FAIL_REGISTER_NOT_READY;
return false;
}
}
else
{
clkObject.systemClockStatus = SYS_CLK_OPERATION_FAIL_NOT_ACHIEVABLE;
*clockClosest = 0;
return false;
}
/* Control is here, means switching operation is either complete or in
progress, not failure */
return true;
}
