请问有人可以发布一些实际工作的C代码来设置主时钟速度吗？

FRM是一个很好的起点。第42部分：具有增强PLL的振荡器：HTTP:/WW1.MICCHIP.COM/DIXBOSS/En/DeVICEDCO/6000 1250B.PDF



      以下为原文

    The FRM is a good place to start. Section 42 - Oscillators with Enhanced PLL.
 
http://ww1.microchip.com/downloads/en/DeviceDoc/60001250B.pdf
 
 

AcLink 2，请共享您的代码。同时，像拉里建议的那样阅读FRM。你应该检查振荡器控制/状态寄存器，以确保事情按需要启用和配置。此外，我非常确信，您应该设置配置词来默认系统的时钟配置。我相信你提到过这一点（通过PrimaMet来设置）。无论哪种方式，你都应该确认这些配置词是通过调试和设置一个断点在你的“主”入口点停在那里，并检查振荡器寄存器（OSCCon等）。这将让你知道你的设置是否已被采纳。



      以下为原文

    Acelink2, please share your code.  As well, read up the FRM as Larry suggested.  You should be checking the oscillator control/status registers to make sure things are enabled and configured as desired.  Also, I am pretty sure that you should be setting up the configuration words to default the system's clocking configuration.  I believe you mentioned this (set via pragma's).  Either way, you should confirm that these configuration words are being programmed by debugging and setting a breakpoint at your 'main' entry point to halt there and inspect oscillator registers (OSCCON, etc.).  This will let you know if your settings have been taken. 

      以下为原文

    285:                 int switch_clock_lprc() {
9D0006C4  27BDFFF8   ADDIU SP, SP, -8
9D0006C8  AFBE0004   SW S8, 4(SP)
9D0006CC  03A0F021   ADDU S8, SP, ZERO
286:                     SYSKEY = 0xaa996655;
9D0006D0  3C02BF80   LUI V0, -16512
9D0006D4  3C03AA99   LUI V1, -21863
9D0006D8  34636655   ORI V1, V1, 26197
9D0006DC  AC430030   SW V1, 48(V0)
287:                     SYSKEY = 0x556699aa;
9D0006E0  3C02BF80   LUI V0, -16512
9D0006E4  3C035566   LUI V1, 21862
9D0006E8  346399AA   ORI V1, V1, -26198
9D0006EC  AC430030   SW V1, 48(V0)
288:                     OSCCONbits.NOSC = 5;
9D0006F0  3C03BF80   LUI V1, -16512
9D0006F4  8C621200   LW V0, 4608(V1)
9D0006F8  24040005   ADDIU A0, ZERO, 5
9D0006FC  7C825204   INS V0, A0, 8, 3
9D000700  AC621200   SW V0, 4608(V1)
289:                     OSCCONbits.OSWEN = 1;
9D000704  3C03BF80   LUI V1, -16512
9D000708  8C621200   LW V0, 4608(V1)
9D00070C  24040001   ADDIU A0, ZERO, 1
9D000710  7C820004   INS V0, A0, 0, 1
9D000714  AC621200   SW V0, 4608(V1)
290:                     while (OSCCONbits.OSWEN);
9D000718  00000000   NOP
9D00071C  3C02BF80   LUI V0, -16512
9D000720  8C421200   LW V0, 4608(V0)
9D000724  30420001   ANDI V0, V0, 1
9D000728  1440FFFC   BNE V0, ZERO, 0x9D00071C
9D00072C  00000000   NOP
291:                     return 0;
9D000730  00001021   ADDU V0, ZERO, ZERO
292:                 }
9D000734  03C0E821   ADDU SP, S8, ZERO
9D000738  8FBE0004   LW S8, 4(SP)
9D00073C  27BD0008   ADDIU SP, SP, 8
9D000740  03E00008   JR RA
9D000744  00000000   NOP