mirror of
https://github.com/STMicroelectronics/STM32CubeF7.git
synced 2025-05-07 19:29:17 +08:00
122 lines
5.9 KiB
Plaintext
122 lines
5.9 KiB
Plaintext
/**
|
||
@page ADC_TripleModeInterleaved Use ADC1, ADC2 and ADC3 in Triple interleaved mode and DMA mode2 with 6Msps
|
||
|
||
@verbatim
|
||
******************************************************************************
|
||
* @file ADC/ADC_TripleModeInterleaved/readme.txt
|
||
* @author MCD Application Team
|
||
* @brief Description of the Triple interleaved mode and DMA mode2 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 use the ADC peripheral to convert a regular channel in Triple
|
||
interleaved mode.
|
||
|
||
The ADC1, ADC2 and ADC3 are configured to convert ADC_CHANNEL_12, with conversion
|
||
triggered by software.
|
||
|
||
The Triple interleaved delay is configured to 5 ADC clk cycles (ADC_TWOSAMPLINGDELAY_5CYCLES).
|
||
|
||
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 ADC1, ADC2 and ADC3 are configured to convert ADC Channel 12.
|
||
|
||
In this example, the system clock is 216MHz, APB2 = 108MHz and ADC clock = APB2/4.
|
||
Since ADCCLK = 27 MHz and Conversion rate = 5 cycles
|
||
==> Conversion Time = 27M/5cyc = 5.4Msps.
|
||
|
||
The ADC measure is realized on PC.02, so you need to connect this pin to a power supply (do not forget to connect the power supply
|
||
GND to the EVAL board GND).
|
||
|
||
STM32 board's LEDs can be used to monitor the transfer status:
|
||
- LED1 is ON when the conversion is complete.
|
||
- LED3 is ON when there are an error in initialization.
|
||
|
||
User should monitor aADCTripleConvertedValue variable to get the converted value.
|
||
|
||
@note Refer to "simulation.xls" file to have the diagram simulation of the example and to get the formula
|
||
with an example showing how to calculate to calculate ADC sampling rate.
|
||
|
||
@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
|
||
|
||
Analog, ADC, Analog to Digital, Triple mode, Interleaved, Continuous conversion, Software Trigger, DMA, Measurement,
|
||
|
||
@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
|
||
|
||
- ADC/ADC_TripleModeInterleaved/Inc/stm32f7xx_hal_conf.h HAL configuration file
|
||
- ADC/ADC_TripleModeInterleaved/Inc/stm32f7xx_it.h DMA interrupt handlers header file
|
||
- ADC/ADC_TripleModeInterleaved/Inc/main.h Header for main.c module
|
||
- ADC/ADC_TripleModeInterleaved/Src/stm32f7xx_it.c DMA interrupt handlers
|
||
- ADC/ADC_TripleModeInterleaved/Src/main.c Main program
|
||
- ADC/ADC_TripleModeInterleaved/Src/stm32f7xx_hal_msp.c HAL MSP file
|
||
- ADC/ADC_TripleModeInterleaved/Src/system_stm32f7xx.c STM32F7xx system source file
|
||
|
||
@par Hardware and Software environment
|
||
|
||
- This example runs on STM32F756xx/STM32F746xx devices.
|
||
|
||
- This example has been tested with STM327x6G-EVAL revB evaluation board and can be
|
||
easily tailored to any other supported device and development board.
|
||
|
||
- STM327x6G-EVAL revB Set-up
|
||
- Connect PC2 to external power supply.
|
||
- To use LED1, ensure that JP24 is in position 2-3
|
||
- To use LED3, ensure that JP23 is in position 2-3
|
||
|
||
@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
|
||
|
||
|
||
*/
|