source/src/vm/ls393.cpp

   1 /*
   2         Skelton for retropc emulator
   3
   4         Author : Takeda.Toshiya
   5         Date   : 2008.04.11-
   6
   7         [ 74LS393 ]
   8 */
   9
  10 #include "ls393.h"
  11
  12 void LS393::write_signal(int id, uint32_t data, uint32_t mask)
  13 {
  14         bool signal = ((data & mask) != 0);
  15         if(prev_in && !signal) {
  16                 uint32_t prev_count = count++;
  17                 for(int i = 0; i < 8; i++) {
  18                         if(outputs[i].count) {
  19                                 int bit = 1 << i;
  20                                 if((prev_count & bit) != (count & bit)) {
  21                                         uint32_t val = (count & bit) ? 0xffffffff : 0;
  22                                         write_signals(&outputs[i], val);
  23                                 }
  24                         }
  25                 }
  26         }
  27         prev_in = signal;
  28 }
  29
  30 #define STATE_VERSION   1
  31
  32 void LS393::save_state(FILEIO* state_fio)
  33 {
  34         state_fio->FputUint32(STATE_VERSION);
  35         state_fio->FputInt32(this_device_id);
  36
  37         state_fio->FputUint32(count);
  38         state_fio->FputBool(prev_in);
  39 }
  40
  41 bool LS393::load_state(FILEIO* state_fio)
  42 {
  43         if(state_fio->FgetUint32() != STATE_VERSION) {
  44                 return false;
  45         }
  46         if(state_fio->FgetInt32() != this_device_id) {
  47                 return false;
  48         }
  49         count = state_fio->FgetUint32();
  50         prev_in = state_fio->FgetBool();
  51         return true;
  52 }
  53