无法使用PIC32MX闪烁简单LED

不要手动设置该位。关闭它，让调试工具控制它。（1）你的振荡器不工作。你选择HS模式。有没有外部晶体连接正确？或（2）您连接到错误的调试引脚。您选择了“ICSUPGX2”。



      以下为原文

   
Do NOT manually set that bit. Leave it off and let the debug tool control it.
 

Either:
[1] your oscillator is not working. You selected HS mode. Do you have an external crystal connected correctly?
or
[2] you are connected to the wrong debug pins. You have selected "ICS_PGx2".
 

谢谢更新。（1）是的，硬件上有8MHz的外部晶体振荡器。编辑：与内部振荡器一起工作。〔2〕我使用了单片机的PIN号26和27。用于调试和编程。编辑：调试工作也很好——卡兰



      以下为原文

    Thanks for update..

[1] Yes, I have External Crystal Oscillator of 8MHz on by Hardware.
Edited : Worked with Internal Oscillator.
[2]
I have used Pin Number 26 and 27 of MCU. For Debugging and Programming.

Edited : Debugging Also Working Fine



--
Karan

此代码是如何配置和选择系统时钟频率的示例，而不使用任何微芯片库函数。请理解，该代码显示了所需的所有步骤。微芯片“隐藏”在微芯片库中的开发人员需要做的一些棘手的事情。LyBrar函数的源代码与编译器一起安装，但是如果没有Microchip库函数，就需要安装PIC32所需的一切。



      以下为原文

    This code is an example of how to configure and select the system clock frequency without using any Microchip library functions.
/*
 * File:   main.c
 * Target: PIC32MX795F512L
 * Compiler: C32 v2.02, XC16 v1.44
 *
 * Description:
 *  Blink LEDs on PORTF bits RF2, RF4, RF8
 *
 * Notes:
 *  Define symbol USE_XTAL to use an external 8.0MHz crystal.
 *  Define symbol USE_PLL to enable the PLL and set clock to 80MHz.
 *  Does not use the PLIB library so should build with any Microchip compiler for PIC32.
 *  When building with XC16 v1.44 MPLAB v8.92 asserts an error dialog box.
 */

/*
 * Configuration words
 */
#pragma config FSRSSEL = PRIORITY_7     /* SRS Select (SRS Priority 7) */
#pragma config FMIIEN = OFF             /* Ethernet RMII/MII Enable (RMII Enabled) */
#pragma config FETHIO = OFF             /* Ethernet I/O Pin Select (Alternate Ethernet I/O) */
#pragma config FCANIO = OFF             /* CAN I/O Pin Select (Alternate CAN I/O) */
#pragma config FUSBIDIO = OFF           /* USB USID Selection (Controlled by Port Function) */
#pragma config FVBUSONIO = OFF          /* USB VBUS ON Selection (Controlled by Port Function) */
#pragma config FPLLIDIV = DIV_2         /* PLL Input Divider (2x Divider) */
#pragma config FPLLMUL = MUL_20         /* PLL Multiplier (20x Multiplier) */
#pragma config UPLLIDIV = DIV_2         /* USB PLL Input Divider (2x Divider) */
#pragma config UPLLEN = OFF             /* USB PLL Enable (Disabled and Bypassed) */
#pragma config FPLLODIV = DIV_1         /* System PLL Output Clock Divider (PLL Divide by 1) */
#pragma config FSOSCEN = OFF            /* Secondary Oscillator Enable (Disabled) */
#pragma config IESO = OFF               /* Internal/External Switch Over (Disabled) */
#pragma config OSCIOFNC = OFF           /* CLKO Output Signal Active on the OSCO Pin (Disabled) */
#pragma config FPBDIV = DIV_1           /* Peripheral Clock Divisor (Pb_Clk is Sys_Clk/1) */
#pragma config WDTPS = PS1              /* Watchdog Timer Postscaler (1:1) */
#pragma config FWDTEN = OFF             /* Watchdog Timer Enable (WDT Disabled (SWDTEN Bit Controls)) */
#pragma config ICESEL = ICS_PGx2        /* ICE/ICD Comm Channel Select (ICE EMUC2/EMUD2 pins shared with PGC2/PGD2) */
#pragma config PWP = OFF                /* Program Flash Write Protect (Disable) */
#pragma config BWP = OFF                /* Boot Flash Write Protect bit (Protection Disabled) */
#pragma config CP = OFF                 /* Code Protect (Protection Disabled) */
#pragma config FNOSC = FRC              /* Oscillator Selection Bits (Fast RC Osc) */
#pragma config FCKSM = CSECMD           /* Clock Switching and Monitor Selection (Clock Switch Enable, FSCM Disabled) */

#if defined(USE_XTAL)

#pragma config POSCMOD = XT             /* Primary Oscillator Configuration (XT osc mode) */
#define OSC_FREQUENCY       (8000000ul) /* External crystal frequency */
#define PLL_INPUT_DIVIDER   (2ul)
#define PLL_MULTIPLIER      (20ul)

#if defined(USE_PLL)
#define OSC_SELECTOR        (0b011)     /* Use Primary Oscillator + PLL*/
#else
#define OSC_SELECTOR        (0b010)     /* Use Primary Oscillator */
#endif

#else

#pragma config POSCMOD = OFF            /* Primary Oscillator Configuration (Primary osc disabled) */
#define OSC_FREQUENCY       (8000000ul) /* Internal Fast RC oscillator frequency */
#define PLL_INPUT_DIVIDER   (2ul)
#define PLL_MULTIPLIER      (20ul)

#if defined(USE_PLL)
#define OSC_SELECTOR        (0b001)     /* Use FRC + PLL */
#else
#define OSC_SELECTOR        (0b000)     /* Use FRC */
#endif

#endif

#if defined(__XC32)
#include
#elif defined(__C32__)
#include
#else
#error "Unknown PIC32 compiler"
#endif



#if defined(USE_PLL)
#define GetSystemClock()        ((OSC_FREQUENCY/PLL_INPUT_DIVIDER)*PLL_MULTIPLIER)
#define PB_CLOCK_DIVIDER        (1ul)
#else
#define GetSystemClock()        (OSC_FREQUENCY)
#define PB_CLOCK_DIVIDER        (1ul)
#endif
#define GetPeripheralClock()    (GetSystemClock()/PB_CLOCK_DIVIDER)
#define GetInstructionClock()   (GetSystemClock())


#define FLASH_SPEED_HZ          30000000ul //Max Flash speed
#define PB_BUS_MAX_FREQ_HZ      80000000ul //Max Peripheral bus speed

/***************************************************************
 *
 *
 * Flash Prefetch option - Values are mutually exclusive
 **************************************************************
 */
#define CHE_CONF_PF_DISABLE  (0 << _CHECON_PREFEN_POSITION)
#define CHE_CONF_PF_C        (1 << _CHECON_PREFEN_POSITION )
#define CHE_CONF_PF_NC       (2 << _CHECON_PREFEN_POSITION)
#define CHE_CONF_PF_ALL      (3 << _CHECON_PREFEN_POSITION)

/* Initialize this PIC */
void __attribute__ ((nomips16)) PIC_Init(void)
{
    // Configure the device for maximum performance,
    // This function will change the program Flash wait states,
    // RAM wait state and enable prefetch cache
    // The PBDIV value must be already set via the pragma FPBDIV option in configuration words.

    unsigned int sys_clock;
    unsigned int pb_clock;
    unsigned int int_status;
    unsigned int wait_states;
    register unsigned long cache_tmp;
    register unsigned long clock_switch_timeout;

    sys_clock = GetSystemClock();

    /* Save current interrupt enable state and disable interrupts */
    asm volatile("di    %0" : "=r"(int_status));

    /* Check that we can change the system clock frequency */
    if(!OSCCONbits.CLKLOCK)
    {
        /* swich system clock to FRC, no PLL */
        SYSKEY = 0, SYSKEY = 0xAA996655, SYSKEY = 0x556699AA;
        OSCCONbits.NOSC = 0b000; /* select FRC as system oscillator */
        OSCCONbits.OSWEN = 1;    /* start a clock switch */
        SYSKEY = 0x33333333;
        for(clock_switch_timeout=80000; clock_switch_timeout; clock_switch_timeout--)
        {
            if(!OSCCONbits.OSWEN) break;
        }
    }
    /* Disable the JTAG interface */
    DDPCONbits.JTAGEN = 0;

    /* Disable the JTAG TDO output */
    DDPCONbits.TDOEN = 0;

    /* Disable the TRACE interface */
    DDPCONbits.TROEN = 0;

    /* Set RAM to use MAX wait states */
    BMXCONCLR = _BMXCON_BMXWSDRM_MASK;

    /* Set FLASH wait states for desired system clock */
    wait_states = 0;
    while(sys_clock > (FLASH_SPEED_HZ * (wait_states + 1)))
    {
        wait_states++;
    }

    /* turn on cache and set FLASH wate states */
    CHECON = CHE_CONF_PF_ALL | wait_states;

    /* Select Kseg0 coherency algorithm as 3, cacheable. */
    asm("mfc0 %0,$16,0" :  "=r"(cache_tmp));
    cache_tmp = (cache_tmp & ~7) | 3;
    asm("mtc0 %0,$16,0" :: "r" (cache_tmp));

    /* compute peripherial bus clock frequency from sys_clock */
    pb_clock = (sys_clock >> OSCCONbits.PBDIV);

    if(!OSCCONbits.CLKLOCK)
    {
        /* swich system clock to Primary oscillation amplifier with PLL */
        SYSKEY = 0, SYSKEY = 0xAA996655, SYSKEY = 0x556699AA;
#if   (PLL_INPUT_DIVIDER == 1)
        OSCCONbits.FRCDIV =0b000;
#elif (PLL_INPUT_DIVIDER == 2)
        OSCCONbits.FRCDIV =0b001;
#elif (PLL_INPUT_DIVIDER == 4)
        OSCCONbits.FRCDIV =0b010;
#elif (PLL_INPUT_DIVIDER == 8)
        OSCCONbits.FRCDIV =0b011;
#elif (PLL_INPUT_DIVIDER == 16)
        OSCCONbits.FRCDIV =0b100;
#elif (PLL_INPUT_DIVIDER == 32)
        OSCCONbits.FRCDIV =0b101;
#elif (PLL_INPUT_DIVIDER == 64)
        OSCCONbits.FRCDIV =0b110;
#elif (PLL_INPUT_DIVIDER == 256)
        OSCCONbits.FRCDIV =0b111;
#else
#error PLL input divider has bad value
#endif

#if   (PLL_MULTIPLIER == 15)
        OSCCONbits.PLLMULT =0b000;
#elif (PLL_MULTIPLIER == 16)
        OSCCONbits.PLLMULT =0b001;
#elif (PLL_MULTIPLIER == 17)
        OSCCONbits.PLLMULT =0b010;
#elif (PLL_MULTIPLIER == 18)
        OSCCONbits.PLLMULT =0b011;
#elif (PLL_MULTIPLIER == 19)
        OSCCONbits.PLLMULT =0b100;
#elif (PLL_MULTIPLIER == 20)
        OSCCONbits.PLLMULT =0b101;
#elif (PLL_MULTIPLIER == 21)
        OSCCONbits.PLLMULT =0b110;
#elif (PLL_MULTIPLIER == 24)
        OSCCONbits.PLLMULT =0b111;
#else
#error PLL multiplier has bad value
#endif
        OSCCONbits.PLLODIV = 0b000; /* set PLL output divider to 1:1 */
        OSCCONbits.NOSC = OSC_SELECTOR;
        OSCCONbits.OSWEN = 1;       /* start a clock switch */
        SYSKEY = 0x33333333;
        for(clock_switch_timeout=80000; clock_switch_timeout; clock_switch_timeout--)
        {
            if(!OSCCONbits.OSWEN) break;
        }
    }

    /* set GPIO pins for digital I/O */
    AD1PCFG = 0xFFFFUL;

    /* Restore interrupt state */
    if(int_status & 0x00000001)
    {
       asm volatile("ei    %0" : "=r"(int_status));
    }
    /*
     * At this point the values for sys_clock and pb_clock
     * should be assigned.
     */
}
/*
 *
 */
void DelayMS( unsigned long Delay )
{
#define TICKS_IN_ONE_MILLISECOND (GetSystemClock() / 2000ul)
    unsigned long Time0, Time1;

    Time0 = _CP0_GET_COUNT(); /* 2 system clocks per count */

    if (Delay < (unsigned long)(0xFFFFFFFF) / TICKS_IN_ONE_MILLISECOND)
        Delay = Delay * TICKS_IN_ONE_MILLISECOND;
    else
        Delay = (unsigned long)(0xFFFFFFFF);

    for(;;)
    {
        Time1 = _CP0_GET_COUNT();
        Time1 = Time1 - Time0;      /* Get cycle from start of spin */
        if (Time1 >= Delay)
            break;
    }
}
/*
 * Main application
 */
#define LED_D1          LATFbits.LATF2
#define LED_D2          LATFbits.LATF8
#define LED_D3          LATFbits.LATF4

#define LED_D1_DIR      TRISFbits.TRISF2
#define LED_D2_DIR      TRISFbits.TRISF8
#define LED_D3_DIR      TRISFbits.TRISF4

void main(void)
{
    int i ;

    PIC_Init();

    DelayMS(1000);

    LED_D1_DIR = 0;
    LED_D2_DIR = 0;
    LED_D3_DIR = 0;

    DelayMS(1000);

    while(1)
    {
        LED_D1   = 0;
        LED_D2   = 1;
        LED_D3   = 0;
        DelayMS(1000);

        LED_D1   = 1;
        LED_D2   = 0;
        LED_D3   = 1;
        DelayMS(1000);
    }
}
Please understand that this code shows all of the steps required. There are several tricky things that must be done that Microchip "hides" from the developer in the Microchip library functions. The source code for the library functions are installed along with the compiler but it can be painful to find everything you need to setup a PIC32 without the Microchip library functions.