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 bool LS393::process_state(FILEIO* state_fio, bool loading)
  33 {
  34         if(!state_fio->StateCheckUint32(STATE_VERSION)) {
  35                 return false;
  36         }
  37         if(!state_fio->StateCheckInt32(this_device_id)) {
  38                 return false;
  39         }
  40         state_fio->StateValue(count);
  41         state_fio->StateValue(prev_in);
  42         return true;
  43 }
  44