DSPIC33F无法使PLL时钟工作

嗨，另一个NOOB问题：我似乎不能让PLL工作。我将不再使用数据表示例代码，除非我切换到PrabMA命令。代码：我用的是LED（RA0）和时钟输出引脚来测量。时钟在7.37兆赫。有什么想法吗？



      以下为原文

    Hi,
Another noob issue: I can't seem to get the PLL to work. I am going off of the datasheet example code, except I switched to pragma commands. Code:
#pragma config GWRP = OFF // General Code Segment Write Protect (User program memory is not write-protected)
#pragma config GSS = OFF // General Segment Code Protection (User program memory is not code-protected)
// FOSCSEL
#pragma config FNOSC = FRC // Oscillator Mode (Internal Fast RC (FRC))
#pragma config IESO = OFF // Internal External Switch Over Mode (Start-up device with FRC, then automatically switch to user-selected oscillator source when ready)
// FOSC
#pragma config POSCMD = NONE // Primary Oscillator Source (HS Oscillator Mode)
#pragma config OSCIOFNC = OFF // OSC2 Pin Function (OSC2 pin has clock out function)
#pragma config IOL1WAY = OFF // Peripheral Pin Select Configuration (Allow Multiple Re-configurations)
#pragma config FCKSM = CSECMD // Clock Switching and Monitor (Clock switching is enabled, Fail-Safe Clock Monitor is disabled)
// FWDT
#pragma config WDTPOST = PS32768 // Watchdog Timer Postscaler (1:32,768)
#pragma config WDTPRE = PR128 // WDT Prescaler (1:128)
#pragma config WINDIS = OFF // Watchdog Timer Window (Watchdog Timer in Non-Window mode)
#pragma config FWDTEN = OFF // Watchdog Timer Enable (Watchdog timer enabled/disabled by user software)
// FPOR
#pragma config FPWRT = PWR128 // POR Timer Value (128ms)
#pragma config ALTI2C = OFF // Alternate I2C pins (I2C mapped to SDA1/SCL1 pins)
// FICD
#pragma config ICS = PGD1 // Comm Channel Select (Communicate on PGC2/EMUC2 and PGD2/EMUD2)
#pragma config JTAGEN = OFF // JTAG Port Enable (JTAG is Disabled

void init_clk(void)
{
/* Program PLL for 38MHz from 7.37MHz HS Xtal */
PLLFBD = 38; // PLL FDBK = 41
CLKDIVbits.PLLPOST = 0; // PLL POST = 2
CLKDIVbits.PLLPRE = 0; // PLL PRE = 2

/* Switch clock source to PLL */
//__builtin_write_OSCCONH(3); // NOSC = 3 : HS + PLL
//__builtin_write_OSCCONL(1); // OSWEN = 1 : switch clock source
    __builtin_write_OSCCONH(0x01);
    __builtin_write_OSCCONL(OSCCON | 0x01);
    // Wait for Clock switch to occur
    while (OSCCONbits.COSC != 0b001);
    // Wait for PLL to lock
    while(OSCCONbits.LOCK!=1) {};
}
I am using the LED (RA0) and also the clock output pin to measure. The clock is at 7.37MHz. Any thoughts?