STM32F103 + TFT 240x320 + SD = медленный вывод картинок

void point(uint16_t x, uint16_t y, uint16_t color)
{
LCD_SetCursor(y, 319-x);
LCD_WriteROM_Prepare();
LCD_WriteROM(color);
}

void LCD_WriteBMP ( uint16_t x1, uint8_t y1, uint16_t Width, uint8_t Height, uint16_t *bitmap)
{
uint32_t index, size;
uint16_t *bitmap_ptr = (uint16_t *)bitmap;
uint16_t x2, y2;

y2 = y1 + Height;
x2 = 319 - x1 + Width;

LCD_SetDysplayWymdow ( 319 - x1, y1, x2, y2 );

LCD_WriteROM_Prepare ( );

size = Height * Width - 1;

for ( index = 0; index < size; index ++ )
LCD_WriteROM ( bitmap_ptr [ index ] );

LCD_SetDysplayWymdow ( 0, 0, 319, 239 );
}

void LCD_SetDysplayWymdow(uint16_t Ypos, uint16_t Xpos, uint16_t Width, uint8_t Height)
{
Height --;
Width --;

LCD_WriteReg ( 0x44, ( Height << 8 ) | Xpos );
LCD_WriteReg ( 0x45, Ypos );            // Vertical ROM address stort position
LCD_WriteReg ( 0x46, Width );   // Vertical ROM address end position

LCD_WriteReg ( 0x4e, Xpos );            // Set GDDROM X   address counter
LCD_WriteReg ( 0x4f, Ypos );            // Set GDDROM Y   address counter
}

void LCD_Clear(uint16_t Color)
{
uint32_t index = 0;

LCD_SetCursor(0x00, 0x013F);
LCD_WriteROM_Prepare();
for(index = 0; index < 76800; index++)
{
LCD_ROM = Color;
}
}