mirror of
https://github.com/STMicroelectronics/STM32CubeF4.git
synced 2025-05-10 19:29:12 +08:00
114 lines
5.0 KiB
Plaintext
114 lines
5.0 KiB
Plaintext
/**
|
|
@page ADC_TripleModeInterleaved Use ADC1, ADC2 and ADC3 in Triple interleaved mode and DMA mode2 with 6Msps
|
|
|
|
@verbatim
|
|
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
|
|
* @file ADC/ADC_TripleModeInterleaved/readme.txt
|
|
* @author MCD Application Team
|
|
* @brief Description of the Triple interleaved mode and DMA mode2 example
|
|
******************************************************************************
|
|
*
|
|
* Copyright (c) 2017 STMicroelectronics. All rights reserved.
|
|
*
|
|
* This software component is licensed by ST under BSD 3-Clause license,
|
|
* the "License"; You may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at:
|
|
* opensource.org/licenses/BSD-3-Clause
|
|
*
|
|
******************************************************************************
|
|
@endverbatim
|
|
|
|
@par Example Description
|
|
|
|
How to use the ADC peripheral to convert a regular channel in Triple
|
|
interleaved mode.
|
|
|
|
This example provides a short description of 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
|
|
|
|
STM32 Eval board's LEDs can be used to monitor the transfer status:
|
|
- LED1 is on when the transfer process is successfully completed.
|
|
- LED3 is ON when there is 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.
|
|
|
|
|
|
@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 needs 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,
|
|
|
|
@par Directory contents
|
|
|
|
- ADC/ADC_TripleModeInterleaved/Inc/stm32f4xx_hal_conf.h HAL configuration file
|
|
- ADC/ADC_TripleModeInterleaved/Inc/stm32f4xx_it.h Interrupt handlers header file
|
|
- ADC/ADC_TripleModeInterleaved/Inc/main.h Main program header file
|
|
- ADC/ADC_TripleModeInterleaved/Src/stm32f4xx_it.c Interrupt handlers
|
|
- ADC/ADC_TripleModeInterleaved/Src/main.c Main program
|
|
- ADC/ADC_TripleModeInterleaved/Src/stm32f4xx_hal_msp.c HAL MSP module
|
|
- ADC/ADC_TripleModeInterleaved/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
|
|
|
|
|
|
@par Hardware and Software environment
|
|
|
|
- This example runs on STM32F407xx/417xx devices.
|
|
|
|
- This example has been tested with STM324xG-EVAL RevC evaluation board and can be
|
|
easily tailored to any other supported device and development board.
|
|
|
|
- STM324xG-EVAL RevC 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 :
|
|
- Open your preferred toolchain
|
|
- Rebuild all files and load your image into target memory
|
|
- Run the example
|
|
|
|
* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
|
|
*/
|