source/src/vm/x1/emm.cpp

   1 /*
   2         SHARP X1 Emulator 'eX1'
   3         SHARP X1twin Emulator 'eX1twin'
   4         SHARP X1turbo Emulator 'eX1turbo'
   5         SHARP X1turboZ Emulator 'eX1turboZ'
   6
   7         Author : Takeda.Toshiya
   8         Date   : 2011.02.17-
   9
  10         [ emm ]
  11 */
  12
  13 #include "emm.h"
  14
  15 namespace X1 {
  16
  17 void EMM::initialize()
  18 {
  19         memset(data_buffer, 0, sizeof(data_buffer));
  20 }
  21
  22 void EMM::reset()
  23 {
  24         data_addr = 0;
  25 }
  26
  27 void EMM::write_io8(uint32_t addr, uint32_t data)
  28 {
  29         switch(addr & 3) {
  30         case 0:
  31                 data_addr = (data_addr & 0xffff00) | data;
  32                 break;
  33         case 1:
  34                 data_addr = (data_addr & 0xff00ff) | (data << 8);
  35                 break;
  36         case 2:
  37                 data_addr = (data_addr & 0x00ffff) | (data << 16);
  38                 break;
  39         case 3:
  40                 if(data_addr < EMM_BUFFER_SIZE) {
  41                         data_buffer[data_addr] = data;
  42                 }
  43                 data_addr = (data_addr + 1) & 0xffffff;
  44                 break;
  45         }
  46 }
  47
  48 uint32_t EMM::read_io8(uint32_t addr)
  49 {
  50         uint32_t data = 0xff;
  51
  52         switch(addr & 3) {
  53         case 3:
  54                 if(data_addr < EMM_BUFFER_SIZE) {
  55                         data = data_buffer[data_addr];
  56                 }
  57                 data_addr = (data_addr + 1) & 0xffffff;
  58                 return data;
  59         }
  60         return 0xff;
  61 }
  62
  63 #define STATE_VERSION   1
  64
  65 bool EMM::process_state(FILEIO* state_fio, bool loading)
  66 {
  67         if(!state_fio->StateCheckUint32(STATE_VERSION)) {
  68                 return false;
  69         }
  70         if(!state_fio->StateCheckInt32(this_device_id)) {
  71                 return false;
  72         }
  73         state_fio->StateBuffer(data_buffer, sizeof(data_buffer), 1);
  74         state_fio->StateUint32(data_addr);
  75         return true;
  76 }
  77
  78 }