mirror of
https://github.com/STMicroelectronics/STM32CubeF7.git
synced 2025-05-11 19:29:34 +08:00
152 lines
7.7 KiB
Plaintext
152 lines
7.7 KiB
Plaintext
/**
|
||
@page LTDC_Display_1Layer LTDC Display Layer 1 example
|
||
|
||
@verbatim
|
||
******************************************************************************
|
||
* @file LTDC/LTDC_Display_1Layer/readme.txt
|
||
* @author MCD Application Team
|
||
* @brief Description of the LTDC Display 1 layer example.
|
||
******************************************************************************
|
||
* @attention
|
||
*
|
||
* Copyright (c) 2016 STMicroelectronics.
|
||
* All rights reserved.
|
||
*
|
||
* This software is licensed under terms that can be found in the LICENSE file
|
||
* in the root directory of this software component.
|
||
* If no LICENSE file comes with this software, it is provided AS-IS.
|
||
*
|
||
******************************************************************************
|
||
@endverbatim
|
||
|
||
@par Example Description
|
||
|
||
How to configure the LTDC peripheral to display a 480x272 RGB888 (24 bits/pixel)
|
||
image on LCD using only one layer.
|
||
|
||
At the beginning of the main program the HAL_Init() function is called to reset
|
||
all the peripherals, initialize the Flash interface and the systick.
|
||
Then the SystemClock_Config() function is used to configure the system
|
||
clock (SYSCLK) to run at 216 MHz.
|
||
|
||
After LCD initialization, the LCD layer 1 is configured to display image
|
||
(modelled by an array) loaded directly from flash memory by LTDC integrated DMA.
|
||
|
||
|
||
LCD_TFT synchronous timings configuration :
|
||
-------------------------------------------
|
||
|
||
Total Width
|
||
<--------------------------------------------------->
|
||
Hsync width HBP Active Width HFP
|
||
<---><--><--------------------------------------><-->
|
||
____ ____|_______________________________________|____
|
||
|___| | | |
|
||
| | |
|
||
__| | | |
|
||
/|\ /|\ | | | |
|
||
| VSYNC| | | | |
|
||
|Width\|/ |__ | | |
|
||
| /|\ | | | |
|
||
| VBP | | | | |
|
||
| \|/_____|_________|_______________________________________| |
|
||
| /|\ | | / / / / / / / / / / / / / / / / / / / | |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
Total | | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
Heigh | | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
|Active| | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
|Heigh | | |/ / / / / / Active Display Area / / / /| |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
| | | |/ / / / / / / / / / / / / / / / / / / /| |
|
||
| \|/_____|_________|_______________________________________| |
|
||
| /|\ | |
|
||
| VFP | | |
|
||
\|/ \|/_____|______________________________________________________|
|
||
|
||
|
||
Each LCD device has its specific synchronous timings values.
|
||
This example uses AM480272H3TMQW-T01H LCD (MB1046 B-01) and configures
|
||
the synchronous timings as following :
|
||
|
||
Horizontal Synchronization (Hsync) = 41
|
||
Horizontal Back Porch (HBP) = 2
|
||
Active Width = 480
|
||
Horizontal Front Porch (HFP) = 2
|
||
|
||
Vertical Synchronization (Vsync) = 10
|
||
Vertical Back Porch (VBP) = 2
|
||
Active Heigh = 272
|
||
Vertical Front Porch (VFP) = 2
|
||
|
||
LCD_TFT windowing configuration :
|
||
---------------------------------
|
||
|
||
To configure the active display window, this example configures the
|
||
horizontal/vertical start and stop.
|
||
|
||
HorizontalStart = (Offset_X + Hsync + HBP);
|
||
HorizontalStop = (Offset_X + Hsync + HBP + Window_Width - 1);
|
||
VarticalStart = (Offset_Y + Vsync + VBP);
|
||
VerticalStop = (Offset_Y + Vsync + VBP + Window_Heigh - 1);
|
||
|
||
Window_width and Window_heigh should be in line with the image size to be
|
||
displayed.
|
||
|
||
STM32 Eval board's LED can be used to monitor the transfer status:
|
||
- LED3 is ON when there is an error in Init process.
|
||
|
||
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
|
||
based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
|
||
a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
|
||
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
|
||
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
|
||
|
||
@note The application need to ensure that the SysTick time base is always set to 1 millisecond
|
||
to have correct HAL operation.
|
||
|
||
@par Keywords
|
||
|
||
Display, LTDC, Display Controller, TFT, LCD, Graphic, RGB888, 1 Layer, BMP,
|
||
|
||
@Note<74>If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
|
||
<20><><EFBFBD><EFBFBD><EFBFBD>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The address and the size of cacheable buffers (shared between CPU and other masters) must be properly updated to be aligned to cache line size (32 bytes).
|
||
|
||
@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Even though the user must manage the cache coherence for read accesses.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
|
||
|
||
@par Directory contents
|
||
|
||
- LTDC/LTDC_Display_2Layers/Inc/stm32f7xx_hal_conf.h HAL configuration file
|
||
- LTDC/LTDC_Display_2Layers/Inc/stm32f7xx_it.h Interrupt handlers header file
|
||
- LTDC/LTDC_Display_2Layers/Inc/main.h Main configuration file
|
||
- LTDC/LTDC_Display_2Layers/Src/stm32f7xx_it.c Interrupt handlers
|
||
- LTDC/LTDC_Display_2Layers/Src/main.c Main program
|
||
- LTDC/LTDC_Display_2Layers/Src/stm32f7xx_hal_msp.c HAL MSP module
|
||
- LTDC/LTDC_Display_2Layers/Src/system_stm32f7xx.c STM32F7xx system clock configuration file
|
||
- LTDC/LTDC_Display_2Layers/Inc/RGB565_480x272.h Image of size 480x272 and format RGB565 to be displayed on LCD
|
||
|
||
@par Hardware and Software environment
|
||
|
||
- This example runs on STM32F756xx/STM32F746xx devices.
|
||
|
||
- This example has been tested with STM327x6G-EVAL board revB and can be
|
||
easily tailored to any other supported device and development board.
|
||
|
||
@par How to use it ?
|
||
|
||
In order to make the program work, you must do the following :
|
||
- Open your preferred toolchain
|
||
- Rebuild all files and load your image into target memory
|
||
- Run the example
|
||
|
||
|
||
*/
|
||
|