/**
  @page ADC_TripleModeInterleaved  Triple interleaved mode and DMA mode2 example 

  @verbatim
  ******************** (C) COPYRIGHT 2013 STMicroelectronics *******************
  * @file    ADC/ADC_TripleModeInterleaved/readme.txt 
  * @author  MCD Application Team
  * @version V1.3.0
  * @date    13-November-2013
  * @brief   Description of the Triple interleaved mode and DMA mode2 example
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  @endverbatim

@par Example Description 

This example shows how to use the ADC peripheral to convert a regular channel
in Triple interleaved mode using DMA in mode 2 with 6Msps.

The Triple interleaved delay is configured 5 ADC clk cycles.

In Triple ADC mode, three DMA requests are generated: 
- On the first request, both ADC2 and ADC1 data are transferred (ADC2 data take 
  the upper half-word and ADC1 data take the lower half-word). 
- On the second request, both ADC1 and ADC3 data are transferred (ADC1 data take
  the upper half-word and ADC3 data take the lower half-word).
- On the third request, both ADC3 and ADC2 data are transferred (ADC3 data take 
  the upper half-word and ADC2 data take the lower half-word) and so on.

On each DMA request (two data items are available) two half-words representing 
two ADC-converted data items are transferred as a word.

A DMA request is generated each time 2 data items are available :
1st request: ADC_CDR[31:0] = (ADC2_DR[15:0] << 16) | ADC1_DR[15:0] (step1)
2nd request: ADC_CDR[31:0] = (ADC1_DR[15:0] << 16) | ADC3_DR[15:0] (step2)
3rd request: ADC_CDR[31:0] = (ADC3_DR[15:0] << 16) | ADC2_DR[15:0] (step3)
4th request: ADC_CDR[31:0] = (ADC2_DR[15:0] << 16) | ADC1_DR[15:0] (step1) and so on.

The conversion is triggered by software.

The ADC1, ADC2 and ADC3 are configured to convert ADC Channel 12.
By this way, the ADC can reach 6Msps, in fact the same channel is converted
each 5 cycles

In this example, the system clock is 144MHz, APB2 = 72MHz and ADC clock = APB2 /2. 
Since ADCCLK= 36MHz and Conversion rate = 5 cycles 
==> Conversion Time = 36M/5cyc = 7.2Msps

 @note Refer to "simulation.xls" file to have the diagram simulation of the example.


@par Directory contents 
  
  - ADC/ADC_TripleModeInterleaved/system_stm32f4xx.c   STM32F4xx system clock configuration file
  - ADC/ADC_TripleModeInterleaved/stm32f4xx_conf.h     Library Configuration file
  - ADC/ADC_TripleModeInterleaved/stm32f4xx_it.c       Interrupt handlers
  - ADC/ADC_TripleModeInterleaved/stm32f4xx_it.h       Interrupt handlers header file
  - ADC/ADC_TripleModeInterleaved/main.c               Main program
  - ADC/ADC_TripleModeInterleaved/main.h               Main program header file

      
@par Hardware and Software environment 

  - This example runs on STM32F405xx/407xx, STM32F415xx/417xx, STM32F427xx/437xx and 
    STM32F429xx/439xx devices.
    
  - This example has been tested with STMicroelectronics STM324xG-EVAL (STM32F40xx/
    STM32F41xx Devices), STM32437I-EVAL (STM32F427xx/STM32F437xx Devices) and 
    STM324x9I-EVAL RevB (STM32F429xx/STM32F439xx Devices) evaluation boards and 
    can be easily tailored to any other supported device and development board.

  - STM324xG-EVAL, STM32437I-EVAL and STM324x9I-EVAL RevB Set-up 
    - Connect PC.2 to a power supply (do not forget to connect the power supply GND
      to the EVAL board GND)


@par How to use it ? 

In order to make the program work, you must do the following:
 - Copy all source files from this example folder to the template folder under
   Project\STM32F4xx_StdPeriph_Templates
 - Open your preferred toolchain 
 - Select the project workspace related to the used device 
   - If "STM32F40_41xxx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM3240_41_G_EVAL\stm324xg_eval.c
           
   - If "STM32F427_437xx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM324x7I_EVAL\stm324x7i_eval.c
          
   - If "STM32F429_439xx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM324x9I_EVAL\stm324x9i_eval.c
                 
 - Rebuild all files and load your image into target memory
 - Run the example

 * <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3>
 */
