player/Project/Src/NES/nes_main.c

//////////////////////////////////////////////////////////////////////////////////
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֲ<EFBFBD><D6B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ye781205<30><35>NESģ<53><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
// ALIENTEK STM32F407<30><37><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
// NES<45><53><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
// <20><><EFBFBD><EFBFBD>ԭ<EFBFBD><D4AD>@ALIENTEK
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̳:www.openedv.com
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>:2014/7/1
// <20>汾<EFBFBD><E6B1BE>V1.0
//////////////////////////////////////////////////////////////////////////////////

#include "nes_main.h"
#include "dac.h"
#include "main.h"
#include "mymem.h"
#include "nes_apu.h"
#include "nes_mapper.h"
#include "nes_ppu.h"
#include "stm32f4xx.h"

#include "ff.h"
#include "string.h"

uint8_t nes_frame_cnt; // nes֡<73><D6A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
int MapperNo;     // map<61><70><EFBFBD><EFBFBD>
int NES_scanline; // nesɨ<73><C9A8><EFBFBD><EFBFBD>
int VROM_1K_SIZE;
int VROM_8K_SIZE;

uint8_t PADdata;  // <20>ֱ<EFBFBD>1<EFBFBD><31>ֵ [7:0]<5D><>7 <20><>6 <20><>5 <20><>4 Start3 Select2 B1 A0
uint8_t PADdata1; // <20>ֱ<EFBFBD>2<EFBFBD><32>ֵ [7:0]<5D><>7 <20><>6 <20><>5 <20><>4 Start3 Select2 B1 A0
uint8_t *NES_RAM; // <20><><EFBFBD><EFBFBD>1024<32>ֽڶ<D6BD><DAB6><EFBFBD>
uint8_t *NES_SRAM;
NES_header *RomHeader; // rom<6F>ļ<EFBFBD>ͷ
MAPPER *NES_Mapper;
MapperCommRes *MAPx;

uint8_t *spr_ram;   // <20><><EFBFBD><EFBFBD>RAM,256<35>ֽ<EFBFBD>
ppu_data *ppu; // ppuָ<75><D6B8>
uint8_t *VROM_banks;
uint8_t *VROM_tiles;

apu_t *apu; // apuָ<75><D6B8>
uint16_t *wave_buffers;
uint16_t *i2sbuf1; // <20><>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD>֡,ռ<><D5BC><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD> 367*4 <20>ֽ<EFBFBD>@22050Hz
uint16_t *i2sbuf2; // <20><>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD>֡,ռ<><D5BC><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD> 367*4 <20>ֽ<EFBFBD>@22050Hz

uint8_t *romfile; // nes<65>ļ<EFBFBD>ָ<EFBFBD><D6B8>,ָ<><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>nes<65>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC>ַ.
//////////////////////////////////////////////////////////////////////////////////////

// <20><>¼nes<65>Ƿ<EFBFBD><C7B7><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>
static uint8_t g_nes_break = 0;

// <20><><EFBFBD><EFBFBD>ROM
// <20><><EFBFBD><EFBFBD>ֵ:0,<2C>ɹ<EFBFBD>
//     1,<2C>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD>
//     3,map<61><70><EFBFBD><EFBFBD>
uint8_t nes_load_rom(void) {
  uint8_t *p;
  uint8_t i;
  uint8_t res = 0;
  p = (uint8_t *)romfile;
  if (strncmp((char *)p, "NES", 3) == 0) {
    RomHeader->ctrl_z = p[3];
    RomHeader->num_16k_rom_banks = p[4];
    RomHeader->num_8k_vrom_banks = p[5];
    RomHeader->flags_1 = p[6];
    RomHeader->flags_2 = p[7];
    if (RomHeader->flags_1 & 0x04)
      p += 512;                           // <20><>512<31>ֽڵ<D6BD>trainer:
    if (RomHeader->num_8k_vrom_banks > 0) // <20><><EFBFBD><EFBFBD>VROM,<2C><><EFBFBD><EFBFBD>Ԥ<EFBFBD><D4A4><EFBFBD><EFBFBD>
    {
      VROM_banks = p + 16 + (RomHeader->num_16k_rom_banks * 0x4000);
#if NES_RAM_SPEED == 1 // 1:<3A>ڴ<EFBFBD>ռ<EFBFBD><D5BC>С 0:<3A>ٶȿ<D9B6>
      VROM_tiles = VROM_banks;
#else
      VROM_tiles = mymalloc(RomHeader->num_8k_vrom_banks * 8 *
                            1024); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>1MB<4D>ڴ<EFBFBD>!!!
      if (VROM_tiles == 0)
        VROM_tiles =
            VROM_banks; // <20>ڴ治<DAB4><E6B2BB><EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>,<2C><><EFBFBD><EFBFBD>VROM_titles<65><73>VROM_banks<6B><73><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>
      compile(RomHeader->num_8k_vrom_banks * 8 * 1024 / 16, VROM_banks,
              VROM_tiles);
#endif
    } else {
      VROM_banks = mymalloc(8 * 1024);
      VROM_tiles = mymalloc(8 * 1024);
      if (!VROM_banks || !VROM_tiles)
        res = 1;
    }
    VROM_1K_SIZE = RomHeader->num_8k_vrom_banks * 8;
    VROM_8K_SIZE = RomHeader->num_8k_vrom_banks;
    MapperNo = (RomHeader->flags_1 >> 4) | (RomHeader->flags_2 & 0xf0);
    if (RomHeader->flags_2 & 0x0E)
      MapperNo = RomHeader->flags_1 >> 4; // <20><><EFBFBD>Ը<EFBFBD><D4B8><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    // printf("use map:%d\r\n",MapperNo);
    for (i = 0; i < 255; i++) // <20><><EFBFBD><EFBFBD>֧<EFBFBD>ֵ<EFBFBD>Mapper<65><72>
    {
      if (MapTab[i] == MapperNo)
        break;
      if (MapTab[i] == -1)
        res = 3;
    }
    if (res == 0) {
      switch (MapperNo) {
      case 1:
        MAP1 = mymalloc(sizeof(Mapper1Res));
        if (!MAP1)
          res = 1;
        break;
      case 4:
      case 6:
      case 16:
      case 17:
      case 18:
      case 19:
      case 21:
      case 23:
      case 24:
      case 25:
      case 64:
      case 65:
      case 67:
      case 69:
      case 85:
      case 189:
        MAPx = mymalloc(sizeof(MapperCommRes));
        if (!MAPx)
          res = 1;
        break;
      default:
        break;
      }
    }
  }
  return res; // <20><><EFBFBD><EFBFBD>ִ<EFBFBD>н<EFBFBD><D0BD><EFBFBD>
}
// <20><><EFBFBD><EFBFBD>NES_RAM<41><4D><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>ʱ<EFBFBD>ĸ<EFBFBD><C4B8><EFBFBD>ָ<EFBFBD><D6B8>
void *nes_ram_alignment;
// <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
void nes_sram_free(void) {
  // myfree(NES_RAM);
  myfree(nes_ram_alignment);
  myfree(NES_SRAM);
  myfree(RomHeader);
  myfree(NES_Mapper);
  myfree(spr_ram);
  myfree(ppu);
  myfree(apu);
  myfree(wave_buffers);
  myfree(i2sbuf1);
  myfree(i2sbuf2);
  myfree(romfile);
  if ((VROM_tiles != VROM_banks) && VROM_banks &&
      VROM_tiles) // <20><><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>ΪVROM_banks<6B><73>VROM_tiles<65><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>,<2C><><EFBFBD>ͷ<EFBFBD>
  {
    myfree(VROM_banks);
    myfree(VROM_tiles);
  }
  switch (MapperNo) // <20>ͷ<EFBFBD>map<61>ڴ<EFBFBD>
  {
  case 1: // <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
    myfree(MAP1);
    break;
  case 4:
  case 6:
  case 16:
  case 17:
  case 18:
  case 19:
  case 21:
  case 23:
  case 24:
  case 25:
  case 64:
  case 65:
  case 67:
  case 69:
  case 85:
  case 189:
    myfree(MAPx);
    break; // <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
  default:
    break;
  }
  NES_RAM = 0;
  NES_SRAM = 0;
  RomHeader = 0;
  NES_Mapper = 0;
  spr_ram = 0;
  ppu = 0;
  apu = 0;
  wave_buffers = 0;
  i2sbuf1 = 0;
  i2sbuf2 = 0;
  romfile = 0;
  VROM_banks = 0;
  VROM_tiles = 0;
  MAP1 = 0;
  MAPx = 0;
}
// ΪNES<45><53><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>
// romsize:nes<65>ļ<EFBFBD><C4BC><EFBFBD>С
// <20><><EFBFBD><EFBFBD>ֵ:0,<2C><><EFBFBD><EFBFBD><EFBFBD>ɹ<EFBFBD>
//        1,<2C><><EFBFBD><EFBFBD>ʧ<EFBFBD><CAA7>
uint8_t nes_sram_malloc(uint32_t romsize) {
  uint16_t i = 0;

  // NES_RAM<41><4D>Ҫ0x800<30><30>С<EFBFBD><D0A1><EFBFBD>ڴ棬<DAB4><E6A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>0x400<30><30><EFBFBD>ڴ棬<DAB4><E6A3AC><EFBFBD><EFBFBD>1024<32>ֽڶ<D6BD><DAB6><EFBFBD>
  nes_ram_alignment = mymalloc(0x800 + 0x400);
  NES_RAM = (void *)(((uint32_t)nes_ram_alignment + 0x400) & 0xfffffc00);

  NES_SRAM = mymalloc(0X2000);
  RomHeader = mymalloc(sizeof(NES_header));
  NES_Mapper = mymalloc(sizeof(MAPPER));
  spr_ram = mymalloc(0X100);
  ppu = mymalloc(sizeof(ppu_data));
  apu = mymalloc(sizeof(apu_t)); // sizeof(apu_t)=  12588
  wave_buffers = mymalloc(APU_PCMBUF_SIZE * 2);
  i2sbuf1 = mymalloc(APU_PCMBUF_SIZE * 4 + 10);
  i2sbuf2 = mymalloc(APU_PCMBUF_SIZE * 4 + 10);
  romfile = mymalloc(romsize); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϸrom<6F>ռ<EFBFBD>,<2C><><EFBFBD><EFBFBD>nes<65>ļ<EFBFBD><C4BC><EFBFBD>С
  if (i == 64 || !NES_RAM || !NES_SRAM || !RomHeader || !NES_Mapper ||
      !spr_ram || !ppu || !apu || !wave_buffers || !i2sbuf1 || !i2sbuf2 ||
      !romfile) {
    nes_sram_free();
    return 1;
  }
  memset(NES_SRAM, 0, 0X2000);                  // <20><><EFBFBD><EFBFBD>
  memset(RomHeader, 0, sizeof(NES_header));     // <20><><EFBFBD><EFBFBD>
  memset(NES_Mapper, 0, sizeof(MAPPER));        // <20><><EFBFBD><EFBFBD>
  memset(spr_ram, 0, 0X100);                    // <20><><EFBFBD><EFBFBD>
  memset(ppu, 0, sizeof(ppu_data));             // <20><><EFBFBD><EFBFBD>
  memset(apu, 0, sizeof(apu_t));                // <20><><EFBFBD><EFBFBD>
  memset(wave_buffers, 0, APU_PCMBUF_SIZE * 2); // <20><><EFBFBD><EFBFBD>
  memset(i2sbuf1, 0, APU_PCMBUF_SIZE * 4 + 10); // <20><><EFBFBD><EFBFBD>
  memset(i2sbuf2, 0, APU_PCMBUF_SIZE * 4 + 10); // <20><><EFBFBD><EFBFBD>
  memset(romfile, 0, romsize);                  // <20><><EFBFBD><EFBFBD>
  return 0;
}

int nes_xoff = 0; // <20><>ʾ<EFBFBD><CABE>x<EFBFBD>᷽<EFBFBD><E1B7BD><EFBFBD><EFBFBD>ƫ<EFBFBD><C6AB><EFBFBD><EFBFBD>(ʵ<><CAB5><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD>=256-2*nes_xoff)
int nes_yoff = 0;

// <20><>ʼnes<65><73>Ϸ
// pname:nes<65><73>Ϸ·<CFB7><C2B7>
// <20><><EFBFBD><EFBFBD>ֵ:
// 0,<2C><><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD>
// 1,<2C>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD>
// 2,<2C>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD>
// 3,<2C><>֧<EFBFBD>ֵ<EFBFBD>map
uint8_t nes_load(uint8_t *pname, void *lcd_addr, int x, int y) {
  nes_xoff = x;
  nes_yoff = y;
  FIL *file;
  FILINFO *file_info;
  UINT br;
  uint8_t res = 0;
  g_nes_break = 0;
  file = mymalloc(sizeof(FIL));
  file_info = mymalloc(sizeof(FILINFO));
  if (file == 0)
    return 1; // <20>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD>ʧ<EFBFBD><CAA7>.

  res = f_stat((char *)pname, file_info);
  if (res != FR_OK) // <20><><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD>ʧ<EFBFBD><CAA7>
  {
    myfree(file);
    myfree(file_info);
    return 2;
  }
  res = nes_sram_malloc(file_info->fsize); // <20><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>
  if (res == 0) {
    f_open(file, (char *)pname, FA_READ);
    f_read(file, romfile, file_info->fsize, &br); // <20><>ȡnes<65>ļ<EFBFBD>
    res = nes_load_rom();                         // <20><><EFBFBD><EFBFBD>ROM
    if (res == 0) {
      Mapper_Init();                      // map<61><70>ʼ<EFBFBD><CABC>
      cpu6502_init();                     // <20><>ʼ<EFBFBD><CABC>6502,<2C><><EFBFBD><EFBFBD>λ
      PPU_reset(lcd_addr);                // ppu<70><75>λ
      apu_init();                         // apu<70><75>ʼ<EFBFBD><CABC>
      nes_sound_open(0, APU_SAMPLE_RATE); // <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>豸
      nes_emulate_frame();                // <20><><EFBFBD><EFBFBD>NESģ<53><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD>
      nes_sound_close();                  // <20>ر<EFBFBD><D8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }
  }
  f_close(file);
  myfree(file); // <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
  myfree(file_info);
  nes_sram_free(); // <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
  return res;
}

// <20><><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4>е<EFBFBD><D0B5><EFBFBD>Ϸ
uint8_t nes_start(uint8_t *file, int fileSize, void *lcd_addr, int x, int y) {
  nes_xoff = x;
  nes_yoff = y;
  uint8_t res = 0;
  g_nes_break = 0;
  res = nes_sram_malloc(fileSize); // <20><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>

  if (res == 0) {
    mymemcpy(romfile, file, fileSize); // <20><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>пռ<D0BF>
    res = nes_load_rom();              // <20><><EFBFBD><EFBFBD>ROM
    if (res == 0) {
      Mapper_Init();                      // map<61><70>ʼ<EFBFBD><CABC>
      cpu6502_init();                     // <20><>ʼ<EFBFBD><CABC>6502,<2C><><EFBFBD><EFBFBD>λ
      PPU_reset(lcd_addr);                // ppu<70><75>λ
      apu_init();                         // apu<70><75>ʼ<EFBFBD><CABC>
      nes_sound_open(0, APU_SAMPLE_RATE); // <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>豸
      nes_emulate_frame();                // <20><><EFBFBD><EFBFBD>NESģ<53><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD>
      nes_sound_close();                  // <20>ر<EFBFBD><D8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }
  }
  nes_sram_free(); // <20>ͷ<EFBFBD><CDB7>ڴ<EFBFBD>
  return res;
}

// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϸ<EFBFBD><CFB7>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD>
void nes_set_window(void) {}

// <20><>ȡ<EFBFBD><C8A1>Ϸ<EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD><EFBFBD>
void nes_get_gamepadval(void) {
#include "usart.h"
  PADdata = USART3_GetKey();
  PADdata1 = 0;
}

// nesģ<73><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD>
void nes_emulate_frame(void) {
  uint8_t nes_frame;
  // TIM3_Int_Init(10000-1,8400-1);//<2F><><EFBFBD><EFBFBD>TIM3 ,1s<31>ж<EFBFBD>һ<EFBFBD><D2BB>
  nes_set_window(); // <20><><EFBFBD>ô<EFBFBD><C3B4><EFBFBD>
  while (1) {
    // LINES 0-239
    PPU_start_frame();
    // LCD_SwitchLayerBuff();//<2F>л<EFBFBD>֡
    for (NES_scanline = 0; NES_scanline < 240; NES_scanline++) {
      run6502(113 * 256);
      NES_Mapper->HSync(NES_scanline);
      // ɨ<><C9A8>һ<EFBFBD><D2BB>
      if (nes_frame == 0)
        scanline_draw(NES_scanline);
      else
        do_scanline_and_dont_draw(NES_scanline);
    }
    // LCD_ExitLayerBuff ();

    NES_scanline = 240;
    run6502(113 * 256); // <20><><EFBFBD><EFBFBD>1<EFBFBD><31>
    NES_Mapper->HSync(NES_scanline);
    start_vblank();
    if (NMI_enabled()) {
      cpunmi = 1;
      run6502(7 * 256); // <20><><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD>
    }
    NES_Mapper->VSync();
    // LINES 242-261
    for (NES_scanline = 241; NES_scanline < 262; NES_scanline++) {
      run6502(113 * 256);
      NES_Mapper->HSync(NES_scanline);
    }
    end_vblank();
    nes_get_gamepadval(); // ÿ3֡<33><D6A1>ѯһ<D1AF><D2BB>USB
    apu_soundoutput();    // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϸ<EFBFBD><CFB7><EFBFBD><EFBFBD>
    nes_frame_cnt++;
    nes_frame++;
    if (nes_frame > NES_SKIP_FRAME)
      nes_frame = 0; // <20><>֡
    uint8_t nesBreak(void);
    if (nesBreak())
      break;
    if (Touch_GetState()->x[1] != 0)
      break;
  }
  // TIM3->CR1&=~(1<<0);//<2F>رն<D8B1>ʱ<EFBFBD><CAB1>3
}

uint8_t nesBreak(void) {
  uint8_t t = 0;
  if ((PADdata & 0x0c) == 0x0c) {
    g_nes_break = 0x0c;
  }
  if ((g_nes_break) && (t = USART3_GetKeyPressed(), t & 0x0c)) {
    g_nes_break &= ~t;
    if (g_nes_break == 0)
      return 1;
  }
  return 0;
}

// <20><>6502.s<><73><EFBFBD>汻<EFBFBD><E6B1BB><EFBFBD><EFBFBD>
void debug_6502(uint16_t reg0, uint8_t reg1) {
  // printf("6502 error:%x,%d\r\n",reg0,reg1);
}

//////////////////////////////////////////////////////////////////////////////////
// nes,<2C><>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD>֧<EFBFBD>ֲ<EFBFBD><D6B2><EFBFBD>

static vu8 g_buff_Invalid = 0; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ЧʱҪ<CAB1><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
static vu8 g_buff_useing;      // <20><>ǰDMA<4D><41>ʹ<EFBFBD><CAB9><EFBFBD>ĸ<EFBFBD><C4B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
static DAC_UserStruct g_dac;

static void dma_tx_callback(DAC_UserStruct *dac) {
  uint16_t i;
  g_buff_useing = dac->buff_useing;
  g_buff_Invalid = 1;
}

// NES<45><53><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD>
int nes_sound_open(int samples_per_sync, int sample_rate) {

  // <20><>ʼ<EFBFBD><CABC>DAC
  g_dac.buff1 = (uint32_t *)i2sbuf1;
  g_dac.buff2 = (uint32_t *)i2sbuf2;
  g_dac.buff_size = APU_PCMBUF_SIZE * 4;
  g_dac.rate = RATE22050;
  g_dac.call_back = dma_tx_callback;
  DAC_NormalInit(&g_dac);
  return 1;
}

// NES<45>ر<EFBFBD><D8B1><EFBFBD>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD>
void nes_sound_close(void) { DAC_NormalDeInit(&g_dac); }

void nes_apu_fill_buffer(int samples, uint16_t *wavebuf) {
  if (DAC_GetDacHander() != &g_dac)
    return;
  uint16_t i;
  uint16_t *p;
  while (g_buff_Invalid == 0) // <20>ȴ<EFBFBD><C8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
  {
    rt_thread_delay(5);
  };
  if (g_buff_useing == 0) {
    p = (uint16_t *)i2sbuf2;
  } else {
    p = (uint16_t *)i2sbuf1;
  }
  {
    for (i = 0; i < APU_PCMBUF_SIZE; i++) {
      p[2 * i] = ((wavebuf[i] + 0x8000) >> 4);
      p[2 * i + 1] = p[2 * i];
    }
  }
  // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA>Ч
  g_buff_Invalid = 0;
}