北邮信号与信息处理DSP实验二

信号与信息综合处理实验报告学院： 班级： 姓名： 学号：实验二FFT实现实验目的进一步熟悉CCSv5的开发环境，掌握调试的要素，并理解FFT的过程。实验原理FFT变换FFT算法：X，蝶形运算图：

实现函数：DSP_fft(w,N,x,y)。IFFT变换算法实现：x实现流程： -14,0,-57,0,-125,0,-217,0,-326,0,-449,0,-578,0,-707,0,-829,0,-938,0,-1027,0, -1090,0,-1122,0,-1119,0,-1079,0,-1000,0,-883,0,-729,0,-541,0,-324,0,-84,0, 173,0,439,0,707,0,968,0,1214,0,1437,0,1631,0,1788,0,1904,0,1976,0 };shortx1[2*N]={0};shortx2[2*N]={0};//存储FFT之后的结果shorty[2*N]= { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };#include<stdio.h>#include<csl.h>#include<csl_irq.h>#include<csl_chip.h>#include<csl_emifa.h>#include"dsk6416.h"#include"dsk6416_led.h"staticEMIFA_ConfigMyEmifaConfig={ EMIFA_GBLCTL_RMK ( EMIFA_GBLCTL_EK2RATE_FULLCLK, //1XEMIFinputclock EMIFA_GBLCTL_EK2HZ_CLK, //eclkout2continueoutputduringhold EMIFA_GBLCTL_EK2EN_ENABLE, //eclkout2enableoutput EMIFA_GBLCTL_BRMODE_MRSTATUS, //busrequestismemoryaccessorrefreshpending/inprogress EMIFA_GBLCTL_NOHOLD_DISABLE, EMIFA_GBLCTL_EK1HZ_CLK, //eclkout1continueoutputduringhold EMIFA_GBLCTL_EK1EN_ENABLE, //eclkout1enableoutput EMIFA_GBLCTL_CLK4EN_ENABLE, //clkout4outputenable EMIFA_GBLCTL_CLK6EN_ENABLE //clkout6outputenable ), 0xffffffd3, //64BITSDRAM// 0xffffff33, //32BITSDRAM// 0xffffff93, //16bitSDRAM// 0xffffff83, //8bitSDRAM 0xffffffe3, 0x22a28a 0x22a28a EMIFA_SDCTL_RMK ( EMIFA_SDCTL_SDBSZ_4BANKS, //SDRAMbanksize4banks EMIFA_SDCTL_SDRSZ_11ROW, //rownumber=11 EMIFA_SDCTL_SDCSZ_8COL, //columnnumber=8 EMIFA_SDCTL_RFEN_ENABLE, //SDRAMrefreshenable //EMIFA_SDCTL_INIT_NO, //SDRAM配置完每个CE空间后，不初始化 EMIFA_SDCTL_INIT_YES, //SDRAM配置完每个CE空间后，初始化 EMIFA_SDCTL_TRCD_OF(2), //TRCD=(Trcd/Tcyc)-1 EMIFA_SDCTL_TRP_OF(2), //TRP=(Trp/Tcyc)-1,3个 EMIFA_SDCTL_TRC_OF(8), EMIFA_SDCTL_SLFRFR_DISABLE //selfrefreshmodedisable ), EMIFA_SDTIM_RMK ( EMIFA_SDTIM_XRFR_DEFAULT, //EXTTIMERdefault EMIFA_SDTIM_PERIOD_OF(2083) //refreshperiod,clockout1=10ns ), EMIFA_SDEXT_RMK ( EMIFA_SDEXT_WR2RD_OF(0), //cyclesbetweenwritetoreadcommand=1,subtract1is0 EMIFA_SDEXT_WR2DEAC_OF(1), //cyclesbetweenwritetoprecharge=2 EMIFA_SDEXT_WR2WR_OF(1), //cyclesbetweenwritetowrite=2 EMIFA_SDEXT_R2WDQM_OF(1), //cyclesbetweenreadtobex=2 EMIFA_SDEXT_RD2WR_OF(0), //cyclesbetweenreadtowrite=1 EMIFA_SDEXT_RD2DEAC_OF(1), // EMIFA_SDEXT_RD2RD_OF(0), // EMIFA_SDEXT_THZP_OF(2), //Troh=3cycle EMIFA_SDEXT_TWR_OF(1), //Twr=1clock+6ns EMIFA_SDEXT_TRRD_OF(0), //Trrd=12ns EMIFA_SDEXT_TRAS_OF(5), //Tras=42ns EMIFA_SDEXT_TCL_OF(1) //caslatency=3clock ), 0x00000002, 0x00000002, 0x00000002, 0x00000002};#pragmaDATA_SECTION(sdram_data,".off_ram");unsignedintsdram_data[0x400000];voidmain(){ inti,m[N]; Uint32good_flag; good_flag=0; DSK6416_init();DSK6416_LED_init();//初始化CSL CSL_init(); //配置EMIFA EMIFA_config(&MyEmifaConfig);for(i=0;i<0x400000;i++){ sdram_data[i]=0;}//FFT会改变x[i]的值，故先将其存入SDRAMprintf("x[i]:");for(i=0;i<2*N;i++){ sdram_data[i]=x[i]; printf("%d",x[i]);}printf("\n"); //FFT DSP_fft(w,N,x,y); //FFT结果y[i]的值，存入SDRAM printf("y[i]:");for(i=0;i<2*N;i++){ sdram_data[i+2*N]=y[i]; printf("%d",y[i]);}printf("\n");//FFT结果y[i]的模值平方printf("m[i]:"); for(i=0;i<N;i++) { m[i]=y[2*i]*y[2*i]+y[2*i+1]*y[2*i+1]; printf("%d",m[i]); } printf("\n"); //IFFT将y[i]共轭除以增益系数N（即FFT点数） for(i=0;i<2*N;i++) { if(i%2==1)y[i]=-y[i]; y[i]=y[i]/N; } //IFFT利用FFT进行IFFT DSP_fft(w,N,y,x2); //IFFTFFT会修改y[i]重新把y[i]从SDRAM中读出 printf("y[i]fromSDRAM:");for(i=0;i<2*N;i++){ y[i]=sdram_data[i+2*N]; printf("%d",y[i]);} printf("\n"); //IFFT将FFT的结果共轭即为IFFT结果printf("x2[i]:"); for(i=0;i<2*N;i++) { if(i%2==1)x2[i]=-x2[i]; printf("%d",x2[i]); } printf("\n"); //FFT将x[i]的值从SDRAM中读出赋给x1[i] printf("x1[i]:"); for(i=0;i<2*N;i++) { x1[i]=sdram_data[i]; printf("%d",x1[i]); } printf("\n"); //将IFFT的结果x2[i]与FFT前的数据x1[i]进行比较 for(i=0;i<2*N;i++) { if(abs(x2[i]-x1[i])>10) { good_flag=0; break; } good_flag=1; } if(good_flag==1) { DSK6416_LED_on(0); DSK6416_LED_on(1); DSK6416_LED_on(2); DSK6416_LED_off(3); printf("IFFTRESULTISOK!\n"); } else { DSK6416_LED_on(0); DSK6416_LED_off(1); DSK6416_LED_off(2); DSK6416_LED_off(3); printf("IFFTRESULTISFAILED!\n"); }流程图SDRAM配置流程图SDRAM配置流程图组内分工功能测试软件平台查看变量：通过View->Variables可以查看各个变量的值。图形显示工具：CCSv5中提供了一个高级图形和图像可视化工具。它可通过图形形式显示数组，并且可采用多种格式。查看m序列中的数值，即观测FFT变换后各点模值的平方。Console控制台显示：x[i]:初始序列，即需要进行FFT变换的64点的实部、虚部按序排列；y[i]:FFT的结果，即变换后64点的实部、虚部按序排列；m[i]:FFT变换所得各点模值平方；x2[i]:IFFT变换结果，即反变换后64点实部、虚部按序排列；x1[i]:从SDRAM读出的x[i]原始序列；结论：“IFFTRESULTISOK!”代表变换前后数据一致，否则显示“IFFTRESULTISFAILED!”。代码优化：如果没有进行软件流水，程序运行结束时，clock显示为：17736121，即程序共需要17736121个时钟周期。优化后，程序运行结束时，clock显示为：52753，即程序共需要52753个时钟周期。DSP执行程序后，LED测试效果为LED0~2均被点亮，即变换前后一致。重点、难点断点调试问题在不同行设置断点，运行结果不同。在本次实验的调试过程中，应注意将断点设置在最后一行以上，以免出现灰断点，保证单次运行的正常进行。此外，通过View->Variables查看各个变量的值，有时会出现原程序执行时不能显示出变量对应值的情况。经过尝试，发现在只需加入单次运行的断点即可解决这一问题。IFFT及其验证在进行IFFT拓展功能时，考虑使用现有函数实现