rtc.c

   1
   2
   3
   4 #include <stdio.h>
   5 #include <time.h>
   6
   7 #include "defs.h"
   8 #include "mem.h"
   9 #include "rtc.h"
  10 #include "rc.h"
  11
  12 struct rtc rtc;
  13
  14 static int syncrtc = 1;
  15
  16 rcvar_t rtc_exports[] =
  17 {
  18         RCV_BOOL("syncrtc", &syncrtc, "resync RTC for elapsed time on load"),
  19         RCV_END
  20 };
  21
  22
  23 void rtc_latch(byte b)
  24 {
  25         if ((rtc.latch ^ b) & b & 1)
  26         {
  27                 rtc.regs[0] = rtc.s;
  28                 rtc.regs[1] = rtc.m;
  29                 rtc.regs[2] = rtc.h;
  30                 rtc.regs[3] = rtc.d;
  31                 rtc.regs[4] = (rtc.d>>9) | (rtc.stop<<6) | (rtc.carry<<7);
  32                 rtc.regs[5] = 0xff;
  33                 rtc.regs[6] = 0xff;
  34                 rtc.regs[7] = 0xff;
  35         }
  36         rtc.latch = b;
  37 }
  38
  39 void rtc_write(byte b)
  40 {
  41         /* printf("write %02X: %02X (%d)\n", rtc.sel, b, b); */
  42         if (!(rtc.sel & 8)) return;
  43         switch (rtc.sel & 7)
  44         {
  45         case 0:
  46                 rtc.s = rtc.regs[0] = b;
  47                 while (rtc.s >= 60) rtc.s -= 60;
  48                 break;
  49         case 1:
  50                 rtc.m = rtc.regs[1] = b;
  51                 while (rtc.m >= 60) rtc.m -= 60;
  52                 break;
  53         case 2:
  54                 rtc.h = rtc.regs[2] = b;
  55                 while (rtc.h >= 24) rtc.h -= 24;
  56                 break;
  57         case 3:
  58                 rtc.regs[3] = b;
  59                 rtc.d = (rtc.d & 0x100) | b;
  60                 break;
  61         case 4:
  62                 rtc.regs[4] = b;
  63                 rtc.d = (rtc.d & 0xff) | ((b&1)<<9);
  64                 rtc.stop = (b>>6)&1;
  65                 rtc.carry = (b>>7)&1;
  66                 break;
  67         }
  68 }
  69
  70 void rtc_tick()
  71 {
  72         if (rtc.stop) return;
  73         if (++rtc.t == 60)
  74         {
  75                 if (++rtc.s == 60)
  76                 {
  77                         if (++rtc.m == 60)
  78                         {
  79                                 if (++rtc.h == 24)
  80                                 {
  81                                         if (++rtc.d == 365)
  82                                         {
  83                                                 rtc.d = 0;
  84                                                 rtc.carry = 1;
  85                                         }
  86                                         rtc.h = 0;
  87                                 }
  88                                 rtc.m = 0;
  89                         }
  90                         rtc.s = 0;
  91                 }
  92                 rtc.t = 0;
  93         }
  94 }
  95
  96 void rtc_save_internal(FILE *f)
  97 {
  98         fprintf(f, "%d %d %d %02d %02d %02d %02d\n%ld\n",
  99                 rtc.carry, rtc.stop, rtc.d, rtc.h, rtc.m, rtc.s, rtc.t,
 100                 (long) time(0));
 101 }
 102
 103 void rtc_load_internal(FILE *f)
 104 {
 105         int rt = 0;
 106         fscanf(
 107                 f, "%d %d %d %02d %02d %02d %02d\n%d\n",
 108                 &rtc.carry, &rtc.stop, &rtc.d,
 109                 &rtc.h, &rtc.m, &rtc.s, &rtc.t, &rt);
 110         while (rtc.t >= 60) rtc.t -= 60;
 111         while (rtc.s >= 60) rtc.s -= 60;
 112         while (rtc.m >= 60) rtc.m -= 60;
 113         while (rtc.h >= 24) rtc.h -= 24;
 114         while (rtc.d >= 365) rtc.d -= 365;
 115         rtc.stop &= 1;
 116         rtc.carry &= 1;
 117         if (rt) rt = (time(0) - rt) * 60;
 118         if (syncrtc) while (rt-- > 0) rtc_tick();
 119 }
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