main.cpp

00001 #include "mbed.h"
00002 #include "FastIO.h"
00003  
00004 DigitalInOut led1(LED1);
00005 FastInOut<LED2> led2;
00006  
00007 Timer t;
00008 #define LOOPS 10000
00009 
00010 void basic_test();
00011 void fixed_write();
00012 void variable_write();
00013 void read();
00014 void operator_toggle();
00015 void input_output();
00016 
00017 void print_results(int digicount, int fastcount);
00018 
00019 int main() {
00020     printf("\r\nStarting test bench\r\n");
00021     
00022     basic_test();
00023     fixed_write();
00024     variable_write();
00025     read();
00026     operator_toggle();
00027     input_output();
00028     
00029     while(1);
00030 }
00031 
00032 void print_results(int digicount, int fastcount) {
00033     float digicycles = (float)digicount / LOOPS * (float)SystemCoreClock / 1000000.0f;
00034     float fastcycles = (float)fastcount / LOOPS * (float)SystemCoreClock / 1000000.0f;
00035     printf("Standard took %.2f cycles, FastIO took %.2f cycles, which is %d%%\r\n", digicycles, fastcycles,(int)(100.0f*fastcycles/digicycles + 0.5));
00036     printf("Standard took %.0fns, FastIO took %.0fns\r\n", (float)digicount/LOOPS * 1000, (float)fastcount/LOOPS * 1000);
00037 }
00038  
00039 void basic_test() {
00040 printf("Verifying basic behavior\r\n");
00041     int error = 0;
00042     led1.output();
00043     led2.output();
00044     led1 = 1;
00045     led2 = 1;
00046     error += (led1.read() != 1);
00047     error += (led2.read() != 1);
00048     led1 = 0;
00049     led2 = 0;
00050     error += (led1.read() != 0);
00051     error += (led2.read() != 0);
00052     
00053     if (error == 0) 
00054         printf("Basic behavior verified\r\n");
00055     else {
00056         printf("Error in basic behavior\r\n");
00057         while(1);
00058     }
00059 }
00060 
00061 
00062 void fixed_write() {
00063     int overhead;
00064     int digitalinout;
00065     int fastinout;
00066     int count;
00067     
00068     printf("\nMeasuring fixed write pattern speed\r\n");
00069     led1.output();
00070     led2.output();
00071     
00072     //Calculate loop overhead
00073     count = LOOPS / 2;
00074     t.reset();
00075     t.start();
00076     while ( count -- ) {
00077         led1.write(1);
00078         led1.write(0);
00079     }
00080     t.stop();
00081     overhead = t.read_us();
00082     
00083     count = LOOPS / 2;
00084     t.reset();
00085     t.start();
00086     while ( count -- )
00087     {
00088         led1.write(1);
00089         led1.write(0);
00090         led1.write(1);
00091         led1.write(0);
00092     }
00093     t.stop();
00094     digitalinout = t.read_us() - overhead;
00095     
00096     //Calculate loop overhead
00097     count = LOOPS / 2;
00098     t.reset();
00099     t.start();
00100     while ( count -- ) {
00101         led2.write(1);
00102         led2.write(0);
00103     }
00104     t.stop();
00105     overhead = t.read_us();
00106     
00107     count = LOOPS / 2;
00108     t.reset();
00109     t.start();
00110     while ( count -- )
00111     {
00112         led2.write(1);
00113         led2.write(0);
00114         led2.write(1);
00115         led2.write(0);
00116     }
00117     t.stop();
00118     fastinout = t.read_us() - overhead;
00119     
00120     print_results(digitalinout, fastinout);
00121 }
00122 
00123 void variable_write() {
00124     int overhead;
00125     int digitalinout;
00126     int fastinout;
00127     int count;
00128     
00129     printf("\nMeasuring variable write pattern speed\r\n");
00130     led1.output();
00131     led2.output();
00132     
00133     //Calculate loop overhead
00134     int value = 1;
00135     count = LOOPS / 2;
00136     t.reset();
00137     t.start();
00138     while ( count -- ) {
00139         value = value - 1; led1.write(value);
00140         value = value - 1; 
00141         value = value - 1;
00142         value = value - 1; led1.write(value);
00143     }
00144     
00145     t.stop();
00146     overhead = t.read_us();
00147 
00148     count = LOOPS / 2;
00149     t.reset();
00150     t.start();
00151     while ( count -- )
00152     {
00153         value = value - 1; led1.write(value);
00154         value = value - 1; led1.write(value);
00155         value = value - 1; led1.write(value);
00156         value = value - 1; led1.write(value);
00157     }
00158     t.stop();
00159     digitalinout = t.read_us() - overhead;
00160     
00161     count = LOOPS / 2;
00162     t.reset();
00163     t.start();
00164     while ( count -- ) {
00165         value = value - 1; led2.write(value);
00166         value = value - 1; 
00167         value = value - 1;
00168         value = value - 1; led2.write(value);
00169     }
00170     
00171     t.stop();
00172     overhead = t.read_us();
00173 
00174     count = LOOPS / 2;
00175     t.reset();
00176     t.start();
00177     while ( count -- )
00178     {
00179         value = value - 1; led2.write(value);
00180         value = value - 1; led2.write(value);
00181         value = value - 1; led2.write(value);
00182         value = value - 1; led2.write(value);
00183     }
00184     t.stop();
00185     fastinout = t.read_us() - overhead;
00186     print_results(digitalinout, fastinout);
00187 }
00188 
00189 void read() {
00190     int overhead;
00191     int digitalinout;
00192     int fastinout;
00193     int count;
00194     
00195     printf("\nMeasuring read speed\r\n");
00196     led1.input(); led1.mode(PullUp);
00197     led2.input(); led2.mode(PullUp);
00198     
00199     //Calculate loop overhead
00200     count = LOOPS;
00201     t.reset();
00202     t.start();
00203     while ( count -- ) {
00204     }
00205     t.stop();
00206     overhead = t.read_us();
00207 
00208     count = LOOPS;
00209     t.reset();
00210     t.start();
00211     while ( count -- )
00212     {
00213         if (led1.read() == 2)       //This shouldn't happen due to pull-up, if you get weird results, it is happening
00214             break;   
00215     }
00216     t.stop();
00217     digitalinout = t.read_us() - overhead;
00218 
00219     count = LOOPS;
00220     t.reset();
00221     t.start();
00222     while ( count -- )
00223     {
00224         if (led2.read() == 2)       //This shouldn't happen due to pull-up, if you get weird results, it is happening
00225             break;       
00226     }
00227     t.stop();
00228     fastinout = t.read_us() - overhead;
00229  
00230     print_results(digitalinout, fastinout);
00231 }
00232 
00233 void operator_toggle() {
00234     int overhead;
00235     int digitalinout;
00236     int fastinout;
00237     int count;
00238     
00239     printf("\nMeasuring toggling using operators speed\r\n");
00240     led1.output();
00241     led2.output();
00242     
00243     //Calculate loop overhead
00244     count = LOOPS / 2;
00245     t.reset();
00246     t.start();
00247     while ( count -- ) {
00248         led1 = !led1;      
00249         led1 = !led1;
00250     }
00251     t.stop();
00252     overhead = t.read_us();
00253 
00254     count = LOOPS / 2;
00255     t.reset();
00256     t.start();
00257     while ( count -- ) {
00258         led1 = !led1;      
00259         led1 = !led1;
00260         led1 = !led1;      
00261         led1 = !led1;
00262     }
00263     t.stop();
00264     digitalinout = t.read_us() - overhead;
00265     
00266     count = LOOPS / 2;
00267     t.reset();
00268     t.start();
00269     while ( count -- ) {
00270         led2 = !led2;
00271         led2 = !led2;
00272     }
00273     t.stop();
00274     overhead = t.read_us();
00275     
00276     count = LOOPS / 2;
00277     t.reset();
00278     t.start();
00279     while ( count -- )
00280     {
00281          led2 = !led2;
00282          led2 = !led2;
00283          led2 = !led2;
00284          led2 = !led2;
00285     }
00286     t.stop();
00287     fastinout = t.read_us() - overhead;
00288     print_results(digitalinout, fastinout);
00289 }
00290 
00291 void input_output() {
00292     int overhead;
00293     int digitalinout;
00294     int fastinout;
00295     int count;
00296     
00297     printf("\nMeasuring switching between input and output\r\n");
00298     
00299     //Calculate loop overhead
00300     count = LOOPS / 2;
00301     t.reset();
00302     t.start();
00303     while ( count -- ) {
00304         led1.input();
00305         led1.output();
00306     }
00307     t.stop();
00308     overhead = t.read_us();
00309 
00310     count = LOOPS / 2;
00311     t.reset();
00312     t.start();
00313     while ( count -- ) {
00314         led1.input();
00315         led1.output();
00316         led1.input();
00317         led1.output();
00318     }
00319     t.stop();
00320     digitalinout = t.read_us() - overhead;
00321     
00322     count = LOOPS / 2;
00323     t.reset();
00324     t.start();
00325     while ( count -- ) {
00326         led2.input();
00327         led2.output();
00328     }
00329     t.stop();
00330     overhead = t.read_us();
00331     
00332     count = LOOPS / 2;
00333     t.reset();
00334     t.start();
00335     while ( count -- )
00336     {
00337         led2.input();
00338         led2.output();
00339         led2.input();
00340         led2.output();
00341     }
00342     t.stop();
00343     fastinout = t.read_us() - overhead;
00344     print_results(digitalinout, fastinout);
00345 }