STM32F4 LTDC

首先配置同步时序先看参考手册

下面看一个实际例子，一块439的开发板

设置：

　　配置时序

  LTDC_InitStruct.LTDC_HorizontalSync = 40;
  /*  */
  LTDC_InitStruct.LTDC_VerticalSync = 9;
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedHBP = 42; 
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedVBP = 11;  
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedActiveW = 522;
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedActiveH = 283;
  /*  */
  LTDC_InitStruct.LTDC_TotalWidth = 524; 
  /*  */
  LTDC_InitStruct.LTDC_TotalHeigh = 285;
            
  LTDC_Init(&LTDC_InitStruct);

注意每个参数定义，之前是累加

看下完整的初始化代码

void LCD_Init(void)
{
  LTDC_InitTypeDef       LTDC_InitStruct;
  LTDC_Layer_InitTypeDef LTDC_Layer_InitStruct;
  LTDC_Layer_TypeDef     LTDC_Layerx;
  
    
  /* IO¿Ú³õʼ»¯ */
  LCD_GPIOInit();
    
  LCD_DisplayOff();
  /* ʹÄÜLCDʱÖÓ */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_LTDC, ENABLE);
  /* ʹÄÜDMAʧ×Ù*/
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2D, ENABLE);
    
  /* ˮƽͬ²½ÐźÅ---µÍµçƽÓÐЧ */
  LTDC_InitStruct.LTDC_HSPolarity = LTDC_HSPolarity_AL;     
  /* ´¹Ö±Í¬²½ÐźÅ---µÍµçƽÓÐЧ */  
  LTDC_InitStruct.LTDC_VSPolarity = LTDC_VSPolarity_AL;     
  /* Êý¾ÝʹÄÜÐźÅ---µÍµçƽÓÐЧ */
  LTDC_InitStruct.LTDC_DEPolarity = LTDC_DEPolarity_AL;     
  /* ÏñËØʱÖÓÅäÖÃ--- */ 
  LTDC_InitStruct.LTDC_PCPolarity = LTDC_DEPolarity_AL;
    /* LCD±³¹âÉèÖà */
  LTDC_InitStruct.LTDC_BackgroundRedValue = 0;            
  LTDC_InitStruct.LTDC_BackgroundGreenValue = 0;          
  LTDC_InitStruct.LTDC_BackgroundBlueValue = 0;      
  /*
   ****************************************************************************
   *PLLSAI_VCO = HSE*PLLSAI_N / PLL_M = 8 * 192 / 8 = 192MHz
   *PLLLCDCLK = PLLSAI_VCO / PLLSAI_R = 192 / 3 = 64 Mhz
   *LTDC clock frequency = PLLLCDCLK / RCC_PLLSAIDivR = 64 / 8 = 8 Mhz
   ****************************************************************************
   */
  RCC_PLLSAIConfig(192, 7, 3);
  RCC_LTDCCLKDivConfig(RCC_PLLSAIDivR_Div4);    
  /* ʹÄÜPLLSAIʱÖÓ */
  RCC_PLLSAICmd(ENABLE);
  /* µÈ´ýPLLSAIʱÖÓ */
  while(RCC_GetFlagStatus(RCC_FLAG_PLLSAIRDY) == RESET){}
  /*  */
  LTDC_InitStruct.LTDC_HorizontalSync = 40;
  /*  */
  LTDC_InitStruct.LTDC_VerticalSync = 9;
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedHBP = 42; 
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedVBP = 11;  
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedActiveW = 522;
  /*  */
  LTDC_InitStruct.LTDC_AccumulatedActiveH = 283;
  /*  */
  LTDC_InitStruct.LTDC_TotalWidth = 524; 
  /*  */
  LTDC_InitStruct.LTDC_TotalHeigh = 285;
            
  LTDC_Init(&LTDC_InitStruct);
        
  LTDC_Layer_InitStruct.LTDC_HorizontalStart = 43;
  LTDC_Layer_InitStruct.LTDC_HorizontalStop = (480 + 43 - 1); 
  LTDC_Layer_InitStruct.LTDC_VarticalStart = 12;
  LTDC_Layer_InitStruct.LTDC_VerticalStop = (272 + 12 - 1);    

  /* Pixel Format configuration*/            
  LTDC_Layer_InitStruct.LTDC_PixelFormat = LTDC_Pixelformat_RGB565;
  /* Alpha constant (255 totally opaque) */
  LTDC_Layer_InitStruct.LTDC_ConstantAlpha = 255; 
  /* Default Color configuration (configure A,R,G,B component values) */          
  LTDC_Layer_InitStruct.LTDC_DefaultColorBlue = 0;        
  LTDC_Layer_InitStruct.LTDC_DefaultColorGreen = 0;       
  LTDC_Layer_InitStruct.LTDC_DefaultColorRed = 0;         
  LTDC_Layer_InitStruct.LTDC_DefaultColorAlpha = 0;
  /* Configure blending factors */       
  LTDC_Layer_InitStruct.LTDC_BlendingFactor_1 = LTDC_BlendingFactor1_CA;    
  LTDC_Layer_InitStruct.LTDC_BlendingFactor_2 = LTDC_BlendingFactor2_CA;
  /* the length of one line of pixels in bytes + 3 then :
     Line Lenth = Active high width x number of bytes per pixel + 3 
     Active high width         = LCD_PIXEL_WIDTH 
     number of bytes per pixel = 2    (pixel_format : RGB565) 
  */
  LTDC_Layer_InitStruct.LTDC_CFBLineLength = ((480 * 2) + 3);
  /*  the pitch is the increment from the start of one line of pixels to the 
      start of the next line in bytes, then :
      Pitch = Active high width x number of bytes per pixel     
  */ 
  LTDC_Layer_InitStruct.LTDC_CFBPitch = (480 * 2);
  /* configure the number of lines */  
  LTDC_Layer_InitStruct.LTDC_CFBLineNumber = 272;

  /* Input Address configuration */    
  LTDC_Layer_InitStruct.LTDC_CFBStartAdress = LCD_FRAME_BUFFER;
   
  LTDC_LayerInit(LTDC_Layer1, &LTDC_Layer_InitStruct);

  /* Configure Layer2 */
  LTDC_Layer_InitStruct.LTDC_CFBStartAdress = LCD_FRAME_BUFFER + BUFFER_OFFSET;
  LTDC_Layer_InitStruct.LTDC_BlendingFactor_1 = LTDC_BlendingFactor1_PAxCA;    
  LTDC_Layer_InitStruct.LTDC_BlendingFactor_2 = LTDC_BlendingFactor2_PAxCA;
  LTDC_LayerInit(LTDC_Layer2, &LTDC_Layer_InitStruct);
    
  LTDC_ReloadConfig(LTDC_IMReload);
  
  /* Enable foreground & background Layers */
  LTDC_LayerCmd(LTDC_Layer1, ENABLE);
//  LTDC_LayerCmd(LTDC_Layer2, ENABLE);
  LTDC_ReloadConfig(LTDC_IMReload);
    
  LCD_DisplayOn();
}

LCD_Init

LTDC_DefaultColorBlue就是背景色

每个Layer支持窗口（Window）操作，所谓Window，就是指该层的图像只有在Window区域内有效，而Window区域外则用该层的DefaultColor填充。如下图：

填色直接写内存

int main (void)
{
  uint32_t i, j;
  uint16_t *addr = (uint16_t *)LCD_FRAME_BUFFER;
    
    
  SDRAM_Init();
  LCD_Init();
    j = 0;
  while (1) {
        
    for (i = 0; i < 0x2000000;i++);
    for (i = 0; i < 480 * 272; i++) 
    {
      addr[i] = 1 << j;
    }
    j++;
    if (j > 15)j = 0;        
  }    
}