时钟频率不对

1万 · 2013-9-24 19:51

2812仿真的时候倍频产生的时钟频率不对

1万 · 2013-9-24 19:52

程序如下：

void InitSysCtrl(void)
{
Uint16 i;
EALLOW;

DevEmuRegs.M0RAMDFT = 0x0300;
DevEmuRegs.M1RAMDFT = 0x0300;
DevEmuRegs.L0RAMDFT = 0x0300;
DevEmuRegs.L1RAMDFT = 0x0300;
DevEmuRegs.H0RAMDFT = 0x0300;


// Disable watchdog module
SysCtrlRegs.WDCR= 0x0068;

// Initalize PLL
SysCtrlRegs.PLLCR = 0xA;
// Wait for PLL to lock
for(i= 0; i< 5000; i++){}

// HISPCP/LOSPCP prescale register settings, normally it will be set to default values
SysCtrlRegs.HISPCP.all = 0x0001;
SysCtrlRegs.LOSPCP.all = 0x0002;
// Peripheral clock enables set for the selected peripherals.
SysCtrlRegs.PCLKCR.bit.EVAENCLK=1;
SysCtrlRegs.PCLKCR.bit.EVBENCLK=1;
SysCtrlRegs.PCLKCR.bit.SCIENCLKA=1;
SysCtrlRegs.PCLKCR.bit.SCIENCLKB=1;

EDIS;

}

产生的时钟频率不对

XPLLDIS脚（140脚）通过一5K电阻连到VCC
不知道是什么问题