常用xs128超频代码
#include <hidef.h> /* common defines and macros */
#include <MC9S12XS128.h> /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12xs128"
void delayms(int ms)
{
int ii,jj;
if (ms<1) ms=1;
for(ii=0;ii<ms;ii++)
for(jj=0;jj<3338;jj++); //40MHz--1ms
}
void SetBusCLK_16M(void)
{
CLKSEL=0X00; // disengage PLL to system
PLLCTL_PLLON=1; // turn on PLL
SYNR=0x00 | 0x01; // VCOFRQ[7:6];SYNdiv[5:0]
// fVCO= 2*fOSC*(SYNdiv + 1)/(REFdiv + 1)
// fPLL= fVCO/(2 × POSTdiv)
// fBUS= fPLL/2
// VCOCLK Frequency Ranges VCOFRQ[7:6]
// 32MHz <= fVCO <= 48MHz 00
// 48MHz < fVCO <= 80MHz 01
// Reserved 10
// 80MHz < fVCO <= 120MHz 11
REFDV=0x80 | 0x01; // REFFRQ[7:6];REFdiv[5:0]
// fREF=fOSC/(REFdiv + 1)
// REFCLK Frequency Ranges REFFRQ[7:6]
// 1MHz <= fREF <= 2MHz 00
// 2MHz < fREF <= 6MHz 01
// 6MHz < fREF <= 12MHz 10
// fREF > 12MHz 11
// pllclock=2*osc*(1+SYNR)/(1+REFDV)=32MHz;
POSTdiv=0x00; // 4:0, fPLL= fVCO/(2xPOSTdiv)
// If POSTdiv = $00 then fPLL is identical to fVCO (divide by one).
_asm(nop); // BUS CLOCK=16M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_32M(void)
{
CLKSEL=0X00; // disengage PLL to system
PLLCTL_PLLON=1; // turn on PLL
SYNR =0x40 | 0x03; // pllclock=2*osc*(1+SYNR)/(1+REFDV)=64MHz;
REFDV=0x80 | 0x01;
POSTdiv=0x00;
_asm(nop); // BUS CLOCK=32M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_40M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x04;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=80MHz;
_asm(nop); //BUS CLOCK=40M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_48M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x05;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=96MHz;
_asm(nop); //BUS CLOCK=48M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_64M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x07;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=128MHz;
_asm(nop); //BUS CLOCK=64M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_80M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x09;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=160MHz;
_asm(nop); //BUS CLOCK=80M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_88M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x0a;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=176MHz;
_asm(nop); //BUS CLOCK=88M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_96M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x0b;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=192MHz;
_asm(nop); //BUS CLOCK=96M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_104M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x0c;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=208MHz;
_asm(nop); //BUS CLOCK=104M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void SetBusCLK_120M(void)
{
CLKSEL=0X00; //disengage PLL to system
PLLCTL_PLLON=1; //turn on PLL
SYNR =0xc0 | 0x0d;
REFDV=0x80 | 0x01;
POSTdiv=0x00; //pllclock=2*osc*(1+SYNR)/(1+REFDV)=240MHz;
_asm(nop); //BUS CLOCK=120M
_asm(nop);
while(！(CRGFLG_LOCK==1)); //when pll is steady ,then use it;
CLKSEL_PLLSEL =1; //engage PLL to system;
}
void main(void) {
/* put your own code here */
unsigned char LedCnt=0;
SetBusCLK_96M(); // 此处选择待设定的总线频率
DDRB=0xff;
DDRA=0x01;
PORTA=0XFE;
PORTB=0XFE;
EnableInterrupts;
for(;;) {
LedCnt=(LedCnt>0XFE?0:++LedCnt);
delayms(500); // 修改延时以修改数据发送频率
//低电平灯亮用这句,注释掉下面那句
PORTB=~LedCnt; // 测试清华版系统板
PORTA_PA0=~PORTA_PA0; // 测试龙丘最小系统板
//PORTB_BIT7=~PORTB_BIT7;
//高电平灯亮用这句,注释掉上面那句
//PORTB=LedCnt;
} /* wait forever */
/* please make sure that you never leave this function */
}
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