avr/timer.c

   1 /*
   2  */
   3
   4
   5 #include "common.h"
   6
   7 #include <avr/interrupt.h>
   8 #include <util/atomic.h>
   9
  10 //#include <stdio.h>
  11
  12
  13 #include "timer.h"
  14
  15 /* timer interrupt/overflow counter */
  16 volatile uint32_t timestamp;
  17
  18
  19 /*---------------------------------------------------------*/
  20 /* 1000Hz timer interrupt generated by OC3A                */
  21 /*---------------------------------------------------------*/
  22
  23 ISR(TIMER3_COMPA_vect)
  24 {
  25         static int_fast8_t tick_10ms;
  26         int_fast8_t i;
  27
  28
  29         timestamp++;
  30
  31         i = tick_10ms + 1;
  32         if (i == 10) {
  33                 i = 0;
  34                 Stat |= S_10MS_TO;
  35
  36                 /* Drive timer procedure of low level disk I/O module */
  37                 //disk_timerproc();
  38         }
  39         tick_10ms = i;
  40
  41 }
  42
  43
  44
  45 /*--------------------------------------------------------------------------*/
  46
  47 #if 0
  48
  49 void do_10ms(void)
  50 {
  51                 if (to_counter)
  52                         to_counter--;
  53 }
  54
  55 #endif
  56
  57 /*--------------------------------------------------------------------------*/
  58
  59
  60 #if 0
  61 void timer_setup(void)
  62 {
  63
  64         /* Clock */
  65         CLKPR = _BV(CLKPCE);
  66         CLKPR = 0;
  67
  68         /* Timer */
  69
  70         OCR1A = F_CPU / 1000 - 1; // Timer1: 1000Hz interval (OC1A)
  71         TCCR1B = 0b00001001;
  72         TIMSK1 = _BV(OCIE1A); // Enable TC1.oca interrupt
  73 }
  74 #endif
  75
  76 uint32_t get_timer(uint32_t base)
  77 {
  78         uint32_t ret;
  79
  80         ATOMIC_BLOCK(ATOMIC_FORCEON)
  81         {
  82                 ret = timestamp;
  83         }
  84         return ret - base;
  85 }
  86