// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();
// Step 2. Initalize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;
// Initialize PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2833x_PieCtrl.c file.
InitPieCtrl();
// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;
// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example. This is useful for debug purposes.
// The shell ISR routines are found in DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_PieVect.c.
//InitPieVectTable();
// Connect the watchdog to the WAKEINT interrupt of the PIE
// Write to the whole SCSR register to avoid clearing WDOVERRIDE bit
EALLOW;
// SysCtrlRegs.SCSR = 0;
EDIS;
// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
EALLOW; // This is needed to write to EALLOW protected registers
PieVectTable.WAKEINT = &wakeint_isr;
EDIS; // This is needed to disable write to EALLOW protected registers
// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
// Step 5. User specific code, enable interrupts:
// Clear the counters
WakeCount = 0; // Count interrupts
LoopCount = 0; // Count times through idle loop
// Enable WAKEINT in the PIE: Group 1 interrupt 8
// Enable INT1 which is connected to WAKEINT:
PieCtrlRegs.PIECTRL.bit.ENPIE = 1; // Enable the PIE block
PieCtrlRegs.PIEIER1.bit.INTx8 = 1; // Enable PIE Gropu 1 INT8
IER |= M_INT1; // Enable CPU int1
EINT; // Enable Global Interrupts
// Reset the watchdog counter
ServiceDog();
EALLOW;
SysCtrlRegs.SCSR = 0;
EDIS;
// Enable the watchdog
EALLOW;
SysCtrlRegs.WDCR = 0x002F;
EDIS;
看门狗初始化代码如上所述，当SysCtrlRegs.SCSR = 2时，能正常进入看门狗中断，而当SysCtrlRegs.SCSR = 0时为何不能实现28335的看门狗复位
