汇编语言

Code Warrior 5.0Target : MC9S12XS128Crystal: 16.000Mhz============================================本程序主要包括以下功能：1.设定系统工作在xxMHZ bus clock时钟下;2.测试龙丘最小系统开发板超频性能:如果LED闪烁，说明芯片正常工作;否则，说明芯片没有正常工作，请检查系统设计;3.也可以测试清华大学最小系统板的超频性能,LED计数，根据灯亮可以读取系统循环了多少次************************************************************************************ *****/#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 systemPLLCTL_PLLON=1; // turn on PLLSYNR=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 11REFDV=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 systemPLLCTL_PLLON=1; // turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 systemPLLCTL_PLLON=1; //turn on PLLSYNR =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 */ }。