📄 dsp280x_sysctrl.c
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// TI File $Revision: /main/3 $
// Checkin $Date: December 8, 2004 14:36:24 $
//###########################################################################
//
// FILE: DSP280x_SysCtrl.c
//
// TITLE: DSP280x Device System Control Initialization & Support Functions.
//
// DESCRIPTION:
//
// Example initialization of system resources.
//
//###########################################################################
// $TI Release: DSP280x V1.10 $
// $Release Date: April 18, 2005 $
//###########################################################################
#include "DSP280x_Device.h" // Headerfile Include File
#include "DSP280x_Examples.h" // Examples Include File
// Functions that will be run from RAM need to be assigned to
// a different section. This section will then be mapped to a load and
// run address using the linker cmd file.
#pragma CODE_SECTION(InitFlash, "ramfuncs");
//---------------------------------------------------------------------------
// InitSysCtrl:
//---------------------------------------------------------------------------
// This function initializes the System Control registers to a known state.
// - Disables the watchdog
// - Set the PLLCR for proper SYSCLKOUT frequency
// - Set the pre-scaler for the high and low frequency peripheral clocks
// - Enable the clocks to the peripherals
void InitSysCtrl(void)
{
// Disable the watchdog
DisableDog();
// Initialize the PLLCR to 0xA
InitPll(0xA);
// Initialize the peripheral clocks
InitPeripheralClocks();
}
//---------------------------------------------------------------------------
// Example: InitFlash:
//---------------------------------------------------------------------------
// This function initializes the Flash Control registers
// CAUTION
// This function MUST be executed out of RAM. Executing it
// out of OTP/Flash will yield unpredictable results
void InitFlash(void)
{
EALLOW;
//Enable Flash Pipeline mode to improve performance
//of code executed from Flash.
FlashRegs.FOPT.bit.ENPIPE = 1;
// CAUTION
//Minimum waitstates required for the flash operating
//at a given CPU rate must be characterized by TI.
//Refer to the datasheet for the latest information.
//Set the Random Waitstate for the Flash
FlashRegs.FBANKWAIT.bit.RANDWAIT = 5;
//Set the Paged Waitstate for the Flash
FlashRegs.FBANKWAIT.bit.PAGEWAIT = 5;
//Set the Waitstate for the OTP
FlashRegs.FOTPWAIT.bit.OTPWAIT = 8;
// CAUTION
//Minimum cycles required to move between power states
//at a given CPU rate must be characterized by TI.
//Refer to the datasheet for the latest information.
//For now use the default count
//Set number of cycles to transition from sleep to standby
FlashRegs.FSTDBYWAIT.bit.STDBYWAIT = 0x01FF;
//Set number of cycles to transition from standby to active
FlashRegs.FACTIVEWAIT.bit.ACTIVEWAIT = 0x01FF;
EDIS;
//Force a pipeline flush to ensure that the write to
//the last register configured occurs before returning.
asm(" RPT #7 || NOP");
}
//---------------------------------------------------------------------------
// Example: KickDog:
//---------------------------------------------------------------------------
// This function resets the watchdog timer.
// Enable this function for using KickDog in the application
void KickDog(void)
{
EALLOW;
SysCtrlRegs.WDKEY = 0x0055;
SysCtrlRegs.WDKEY = 0x00AA;
EDIS;
}
//---------------------------------------------------------------------------
// Example: DisableDog:
//---------------------------------------------------------------------------
// This function disables the watchdog timer.
void DisableDog(void)
{
EALLOW;
SysCtrlRegs.WDCR= 0x0068;
EDIS;
}
//---------------------------------------------------------------------------
// Example: InitPll:
//---------------------------------------------------------------------------
// This function initializes the PLLCR register.
void InitPll(Uint16 val)
{
volatile Uint16 iVol;
// Make sure the PLL is not running in limp mode
if (SysCtrlRegs.PLLSTS.bit.MCLKSTS != 1)
{
if (SysCtrlRegs.PLLCR.bit.DIV != val)
{
EALLOW;
// Before setting PLLCR turn off missing clock detect
SysCtrlRegs.PLLSTS.bit.MCLKOFF = 1;
SysCtrlRegs.PLLCR.bit.DIV = val;
EDIS;
// Optional: Wait for PLL to lock.
// During this time the CPU will switch to OSCCLK/2 until
// the PLL is stable. Once the PLL is stable the CPU will
// switch to the new PLL value.
//
// This time-to-lock is monitored by a PLL lock counter.
//
// Code is not required to sit and wait for the PLL to lock.
// However, if the code does anything that is timing critical,
// and requires the correct clock be locked, then it is best to
// wait until this switching has completed.
// The watchdog should be disabled before this loop, or fed within
// the loop.
DisableDog();
// Wait for the PLL lock bit to be set.
// Note this bit is not available on 281x devices. For those devices
// use a software loop to perform the required count.
while(SysCtrlRegs.PLLSTS.bit.PLLLOCKS != 1) { }
EALLOW;
SysCtrlRegs.PLLSTS.bit.MCLKOFF = 0;
EDIS;
}
}
// If the PLL is in limp mode, shut the system down
else
{
// Replace this line with a call to an appropriate
// SystemShutdown(); function.
asm(" ESTOP0");
}
}
//--------------------------------------------------------------------------
// Example: InitPeripheralClocks:
//---------------------------------------------------------------------------
// This function initializes the clocks to the peripheral modules.
// First the high and low clock prescalers are set
// Second the clocks are enabled to each peripheral.
// To reduce power, leave clocks to unused peripherals disabled
//
// Note: If a peripherals clock is not enabled then you cannot
// read or write to the registers for that peripheral
void InitPeripheralClocks(void)
{
EALLOW;
// HISPCP/LOSPCP prescale register settings, normally it will be set to default values
SysCtrlRegs.HISPCP.all = 0x0001;
SysCtrlRegs.LOSPCP.all = 0x0002;
SysCtrlRegs.XCLK.bit.XCLKOUTDIV=2;
// Peripheral clock enables set for the selected peripherals.
// If you are not using a peripheral you may want to leave
// the clock off to save on power.
//
// Note: not all peripherals are available on all 280x derivates.
// Refer to the datasheet for your particular device.
SysCtrlRegs.PCLKCR0.bit.ADCENCLK = 1; // ADC
SysCtrlRegs.PCLKCR0.bit.I2CAENCLK = 1; // I2C
SysCtrlRegs.PCLKCR0.bit.SPIAENCLK=1; // SPI-A
SysCtrlRegs.PCLKCR0.bit.SPIBENCLK=1; // SPI-B
SysCtrlRegs.PCLKCR0.bit.SPICENCLK=1; // SPI-C
SysCtrlRegs.PCLKCR0.bit.SPIDENCLK=1; // SPI-D
SysCtrlRegs.PCLKCR0.bit.SCIAENCLK=1; // SCI-A
SysCtrlRegs.PCLKCR0.bit.SCIBENCLK=1; // SCI-B
SysCtrlRegs.PCLKCR0.bit.ECANAENCLK=1; // eCAN-A
SysCtrlRegs.PCLKCR0.bit.ECANBENCLK=1; // eCAN-B
SysCtrlRegs.PCLKCR1.bit.ECAP1ENCLK = 1; // eCAP1
SysCtrlRegs.PCLKCR1.bit.ECAP2ENCLK = 1; // eCAP2
SysCtrlRegs.PCLKCR1.bit.ECAP3ENCLK = 1; // eCAP3
SysCtrlRegs.PCLKCR1.bit.ECAP4ENCLK = 1; // eCAP4
SysCtrlRegs.PCLKCR1.bit.EPWM1ENCLK = 1; // ePWM1
SysCtrlRegs.PCLKCR1.bit.EPWM2ENCLK = 1; // ePWM2
SysCtrlRegs.PCLKCR1.bit.EPWM3ENCLK = 1; // ePWM3
SysCtrlRegs.PCLKCR1.bit.EPWM4ENCLK = 1; // ePWM4
SysCtrlRegs.PCLKCR1.bit.EPWM5ENCLK = 1; // ePWM5
SysCtrlRegs.PCLKCR1.bit.EPWM6ENCLK = 1; // ePWM6
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Enable TBCLK within the ePWM
SysCtrlRegs.PCLKCR1.bit.EQEP1ENCLK = 1; // eQEP1
SysCtrlRegs.PCLKCR1.bit.EQEP2ENCLK = 1; // eQEP2
EDIS;
}
//===========================================================================
// End of file.
//===========================================================================
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