STM32CubeF4

@verbatim
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
* @file FMC/FMC_SDRAM_DataMemory/readme.txt
* @author MCD Application Team
* @brief Description of the FMC SDRAM example.
******************************************************************************
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@endverbatim

@par Example Description

This example describes how to configure the FMC controller to access the SDRAM
memory including heap and stack.

This example guides you through the different configuration steps by mean of HAL API
to configure the FMC controller to access the MT48LC4M16A2P-6A SDRAM memory mounted
on STM32446E-EVAL evaluation board (including heap and stack).

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 180 MHz.

The example scenario does not reflect a real application case, its purpose is to
provide only the procedure to follow to use the external SDRAM as data memory.

This example does not use the default library startup file. It uses a modified
startup file provided with the example. The user has to add the new startup
file in the project source list. While startup, the SDRAM memory is configured
and initialized to be ready to contain data.

The user has to configure his preferred toolchain using the provided linker file.
The RAM zone is modified in order to use the external SDRAM memory as a RAM.

At this stage, all the used data can be located in the external SDRAM memory.

The user can use the debugger's watch to evaluate "uwTabAddr" and "MSPValue" variables
values which should be above 0xC0000000.

If uwTabAddr and MSPValue values are in the external SDRAM memory, LED1 is ON, otherwise the LED3 is ON.

@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 Directory contents

- FMC/FMC_SDRAM_DataMemory/Inc/stm32f4xx_hal_conf.h HAL configuration file
- FMC/FMC_SDRAM_DataMemory/Inc/main.h Header for main.c module
- FMC/FMC_SDRAM_DataMemory/Inc/stm32f4xx_it.h Interrupt handlers header file
- FMC/FMC_SDRAM_DataMemory/Src/main.c Main program
- FMC/FMC_SDRAM_DataMemory/Src/stm32f4xx_it.c Interrupt handlers
- FMC/FMC_SDRAM_DataMemory/Src/system_stm32f4xx.c STM32F4xx system source file

@par Hardware and Software environment

- This example runs on STM32F446xx devices.

- This example has been tested with STM32446E-EVAL board 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