performance_test.c

   1 /*
   2  * author: Daniel Otte
   3  * email:  daniel.otte@rub.de
   4  * license: GPLv3
   5  *
   6  *
   7  **/
   8
   9 #include "config.h"
  10 #include <string.h>
  11 #include <stdint.h>
  12 #include <stdlib.h>
  13 #include <avr/io.h>
  14 #include <avr/interrupt.h>
  15 #include <avr/pgmspace.h>
  16 #include "uart.h"
  17 #include "performance_test.h"
  18
  19
  20 #ifdef ATMEGA644
  21         #define TIMSK TIMSK1
  22 #endif
  23
  24
  25
  26 uint32_t ovfcounter;
  27
  28 uint16_t const_overhead=0;
  29 uint16_t int_overhead=0;
  30
  31 ISR(TIMER1_OVF_vect){
  32         ovfcounter++;
  33 }
  34
  35 void calibrateTimer(void){
  36         startTimer(1);
  37         stopTimer();
  38         const_overhead = TCNT1;
  39         startTimer(1);
  40         TCNT1=0xFFFE;
  41         ; ; ; ;
  42 //      asm volatile("NOP\n"::); asm volatile("NOP\n"::);
  43         stopTimer();
  44         int_overhead = TCNT1;
  45 }
  46
  47 void startTimer(uint8_t granularity){
  48         TCCR1B = 0; /* stop timer */
  49         TCNT1  = 0;
  50         ovfcounter = 0;
  51         TCCR1A = 0x00;
  52         TIMSK &= 0xC3;
  53         TIMSK |= _BV(TOIE1); /* enable TOIE1 */
  54         TCCR1B = granularity & 0x7;     /* start timer */
  55 }
  56
  57 uint64_t stopTimer(void){
  58         TCCR1B = 0; /* stop timer */
  59         uint64_t ret;
  60         ret = (ovfcounter<<16) | TCNT1;
  61         ret -= const_overhead;
  62         ret -= ovfcounter * int_overhead;
  63         return ret;
  64 }
  65
  66 void getOverhead(uint16_t* constoh, uint16_t* intoh){
  67         *constoh = const_overhead;
  68         *intoh   = int_overhead;
  69 }
  70
  71 void print_time_P(PGM_P s, uint64_t t){
  72         char sv[16];
  73         uint8_t c;
  74         uart_putstr_P(PSTR("\r\n"));
  75         uart_putstr_P(s);
  76         ultoa((unsigned long)t, sv, 10);
  77         for(c=strlen(sv); c<11; ++c){
  78                 uart_putc(' ');
  79         }
  80         uart_putstr(sv);
  81 }
  82
  83 void print_overhead(void){
  84         char str[16];
  85         uart_putstr_P(PSTR("\r\n\r\n=== benchmark ==="));
  86         utoa(const_overhead, str, 10);
  87         uart_putstr_P(PSTR("\r\n\tconst overhead:     "));
  88         uart_putstr(str);
  89         utoa(int_overhead, str, 10);
  90         uart_putstr_P(PSTR("\r\n\tinterrupt overhead: "));
  91         uart_putstr(str);
  92 }
  93
  94