How to use DMA2D

Hello Dear Engineers,

I am looking for using DMA2D with stm32f429IGT6. So far I have been able to use RAM and LCD in cooperation. Now I want to use LVGL as the main framework. The main problem is I don't know how should I use dma2d in the bare-metal case. I was able to use it with Touchgfx, but the configuration then is made by stm32cubemx and the Touchgfx designer.

The flush routine is as follows

static void tft_lcd_flush_cb(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_p) 
{
	for(int y = area->y1; y <= area->y2; y++)
 	for(int x = area->x1; x <= area->x2; x++)
			LCD_FB[x+(y * LV_HOR_RES_MAX)]=(color_p++->full); //pixelColor;
//	HAL_DMA2D_Start(&hdma2d, &color_p[0], &LCD_FB[0], 800, 480);
//	lv_gpu_stm32_dma2d_fill(LCD_FB, 800*480, color_p, 800, 480);
	lv_disp_flush_ready(drv);
}

In the code above, LCD_FB is a pointer to the LCD address which is associated with external RAM. In the mentioned code, the nested for{for{}} are working perfectly, but the two commented code lines are not working as an alternate for the nested for{for{}}.

As for the DMA2D, I have used only

MX_DMA2D_Init();

Is there any other configuration I should implement?

Your help is appreciated

Sincerely yours

[Petr DAVID]

Hello Vahid Ajalluian,

I cannot tell if the configuration of the DMA2D is alright, but I think that after HAL_DMA2D_Start() you should wait for end of transfer with HAL_DMA2D_PollForTransfer(). This procedure is explained in the user manual of the STM32F4 HAL libraries UM1725 page 237. I would also recommend to check the DMA2D examples in STM32F4Cube FW package.

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