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Questions tagged [dma]

Direct memory access (DMA) is a feature of computerized systems that allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU).

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STM32f103 DMA with PWM repeating values

I have a Blue Pill (STM32F103) and connected to it a ws2812b led strip. I am trying to send data to the led strip via PWM over the TIM2 peripheral (Pin A0). To change the duty cycle of the TIM2 PWM I ...
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76 views

STM32L433 Idle + DMA UART Receive not receiving the expected number of bytes

I am currently having an issue with receiving long packets over UART using DMA on a STM32L433 MCU. The UART is set up to interrupt when the line goes IDLE and I then process the newly received byte ...
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1answer
782 views

What do these arrows on a pinout represent?

What do these arrows represent? Is there any way to memorize it easily?
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1answer
80 views

Does not trigger an interrupt DMA when reading SPI. Last byte transaction not coming

I use DMA for reading with SPI flash using USART. MCU - master, flash - slave. I read 1029 bytes per transaction. Exchange algorithm: I activate the flash (CS = 0) I configure the DMA channel to ...
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263 views

STM32 HAL SD CARD SDIO + DMA

I have a problem with SDIO + DMA. I wrote this part of code to SD CARD using FatFS : ...
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0answers
147 views

Decoding mp3 with Helix lib on Stm32f411

I'm sending mp3 self-contained frames from PC to my STM32f411(Discovery board) via FTDI, on microcontroller I decode frame and send decoded pcm data to external DAC codec(on a board) via I2S. I'm ...
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38 views

Invalid read data when using DMA for SPI with flash

To read 100 bytes from SPI flash I need to send 5 byte commands and 100 bytes of fictitious write. I configured 2 DMA channels for sending 105 bytes and 3 channels for receiving 105 bytes respectively....
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1answer
254 views

TIM2 DMA configuration for stm32h7

My problem: I can't configure DMA to working properly on Input Capture event. Data doesn't transfered and error occurs. ...
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0answers
68 views

STM32F4 - DMA, Arbiter, interrupt, stream priority

Does the DMA arbiter interrupt one stream (during transfer) to give access to another stream with higher priority? Or just the arbiter give access before transfer begin so when one stream started ...
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91 views

Changing PWMs parameters on STM32 board

I am trying to change the values of Prescaler, Autoreload and Pulse of PWM using Serial communication on a stm32 Nucleo-F091RC. For the most part I am able to do so since the below code works fine: ...
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147 views

How to store DMA buffer array?

I am trying to store DMA buffer array such as below; ////////////////////Global Area;//////////////////////////////////////// ...
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0answers
30 views

How to use DMA with LPTIM effectively in STM32L011K4?

I want to read ADC data from 2 channels using the STM32L011 microcontroller. I can successfully read in int main () by calling the ...
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240 views

STM32F7 + TI ADS127L01: SPI with DMA circular mode + Timer IC for data ready signal + CRC

I've connected a TI ADS127L01 to the SPI2 of a STM32F746 mcu via SPI2 and Timer 2 Channel 4 input capture for the data ready signal. As soon the data ready signal is captured, the SPI TX DMA (which is ...
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2answers
409 views

Configuring the DMA request multiplexer on a STM32H7 MCU

I have recently switched to the newly-produced SM32H7 MCUs and I am currently in the process of migrating some of my old code to them (I want to see how they handle some applications that require a ...
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121 views

STM32 PWM generates excessive pulses

I use STM32F103C8T6 to drive WS2812 RGB LED strip. So I try to setup TIM1 to generate PWM using DMA. Everything works fine except the fact that I get more waves then I requested. Almost all the code I ...
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1answer
108 views

How to reconstruct input signal by using DAC?

I am working on a project in which - I have to continuously monitor the the ADC input on a microcontroller(STM32F407) and check if the value crosses a certain threshold. If the value crosses the ...
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555 views

STM32F7 Timer and DMA

I'm currently trying to adapt the example project TIM_DMA of the F769I_EVAL to the STM32F746G discovery board. I'm quite new to STM32 and this might be an obvious error. The code creates a timer and ...
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1answer
53 views

DMA transfert data

I have 2 image files imported by ENVI tool (png or raster file), and they are stored in my hard disk, I want to transfer this data from host PC to target FPGA using DMA (Data Memory Access). My ...
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2answers
126 views

Where is the location of display buffer on a computer board? [closed]

On an OS development text by Nick Blundel, at chapter 4.1 titled Adapting to Life Without BIOS, it is explained that while graphics hardware is in text-mode, we can write ASCII characters on screen by ...
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1answer
681 views

ADC DMA on STM32, Nucleo F334R8 stops main while loop from executing

I am am reading ADC via DMA on the STM32 Nucleo F334R8. However, after I start the DMA using the code below, the main while loop fails to execute ...
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80 views

Stm32 Usart crash DMA transfer to TIMER

Hi i wrote driver for stepper motor. I am using DMA transfer. Without USART Config my code works, and i can transfer periods. When i init usart config Motor no accelerate (const value). Can you tell ...
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1answer
35 views

STM32F10x DMA a constant value

does anyone know if it's possible to DMA a constant value using the STM32F103? I've scrutinized the datasheet but can't see anything obvious and nothing via Google either. Could do a single word in ...
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1answer
170 views

Stm32F103 DMA TIM1 - Load 50% of period.

I wrote a code using DMA with TIM1. In DMA buffer i load diffrent periods and send to ARR Register. How Can I change a Pulse of PWM to 50% from Dma buffer ? ...
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788 views

STM32F - how to config DMA transfer to SPI triggered by Timer?

I am trying to make a project with the STM32F746ZG Nucleo board using the DMA to make a transfer of 16-bit values to a DAC connected to the MCU by SPI. I am using the STM32CubeMX to generate the init ...
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1answer
174 views

[STM32F103RB][C] - DMA, can't change PWM period

Hello i woul'd like change PWM period with DMA. I wrote code but i don't know why LED BLINKING with constant time ...
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0answers
289 views

STMF4 ADC conversion seems slow

I'm using an STM32F4 to do some 12 bit conversions. I see from here that I should have hopes of getting somewhere around 1us per conversion, and since I'm doing 2 conversions, I would expect ...
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259 views

Timer DMA requests through DMA1 clarification (stm32f722ze

I need some clarification on this, as it will help my program run smoother. I want to run 2 DMA's simultaneously. One which will send data out using the SDMMC1, which is linked to DMA2. Then I'd like ...
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1answer
971 views

STM32 HAL Using ADC with DMA affects UART transmission

I am using STM32 Nucleo F334R8 board. I transmit some data using UART in asynchronous mode to my PC using: ...
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0answers
252 views

Working i2s with adc (stm32)

I'm trying to get i2s and adc to work together in stm32f4 board. Here is my code to generate a simple saw wave, and output via CS43L22 ...
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1answer
219 views

Unkown issue while parsing a usart fifo buffer

I have an stm32f429-disco configured for USART (Tx and Rx).Communicating with an asynchronous device. The receive data length is not known before hand. It generally varies from 2 bytes to 28 bytes. ...
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0answers
204 views

stm32f4 timer to gpio with dma

I am using stm32f4 and HAL library. I am working a project which is about timer(PWM Generation No Output) to GPIO with DMA. I can't see any output. How can I do it? I couldn't see any output. I set ...
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6answers
6k views

Why not always use DMA in favor of interrupts with UART on STM32? [closed]

I spend last month a lot of time getting UART (for MIDI) to work with an STM (STM32F103C8T6) using interrupts, without very much success. However, this evening using DMA it worked quite fast. Since ...
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2answers
119 views

STM32F103ZET6 USART with DMA behaves differently in debug versus reset run

I am using the STM32F103ZET6 MCU and am having a weird problem where if I program and debug or program and reset my MCU the USART3 used to communicate with a slave device does not work. In debug there ...
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1answer
434 views

16bit DMA UART w/ STM32F4

How do I transmit 16 bits of data with UART to a 16 bit array? I've got two elements in my array, my UART is set up as 8N1 and my DMA is set to circular. I'm using some HAL stuff, and here's my ...
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3answers
975 views

stm32 gpio to dma

I have a few questions regarding using the DMA of the stm32f7 board (nucleo F722ZE ). 1) So to get started I'll explain what I'm doing: I need to read data from 2 GPIO pins (ADC) and will have a ...
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1answer
3k views

STM32 HAL UART Transmit DMA problem

After setting up my project for a custom STM32F7 board which includes a FT2232H UART<->USB converter I got multiple problems when sending (and receiving data). The code I use is mostly generated by ...
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1answer
692 views

STM32F4 How to stop triple interleaved mode?

I am using triple interleaved mode with DMA in STM32F429 and have problem stopping it. It should be stopped by HAL_ADCEx_MultiModeStop_DMA(&hadc1), but while ...
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1answer
112 views

PCIe DMA transcation to multiple PC RAM slots from FPGA

An FPGA endpoint needs to needs to transfer large quantities of data to the host processor's RAM over DMA. So memory mapping to a single RAM might not be possible. Normally high end PCs or Servers ...
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695 views

4-bit parallel data bus using DMA and GPIO on STM32?

It's possible to generate 8 or 16-bit parallel output on an STM32 by using DMA to transfer from a buffer to the ODR register of a GPIO port, by transferring either a byte or a word at a time. However ...
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1answer
263 views

Microchip PIC24's DMA doesn't work as expected

I am trying to configure the DMA in Microchip's PIC24FJ1024, DMA channel will transfer Data, from Source to Destination, every time the program trigger the DMA Channel. One Shot Mode SRC increments ...
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1answer
194 views

HOLD signal in 8085

What happens to an 8085 system if a square wave signal of 1KHz frequency is applied to the HOLD signal of 8085? The frequency of operation is 2MHz. Therefore, if the every 0.5ms, the HOLD pin goes ...
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1answer
413 views

DMA circular input

I want to copy the same value, say 0.0f, into a big block of SDRAM through DMA. For example, STM Discovery 429 uses DMA2D for fast screen clearing with the ...
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1answer
3k views

DMA triggered by Timer using STM32F4-Discovery board

I am trying to trigger the DMA peripheral by the Timer using STM32F4-Discovery board, but it doesn't seem to work. I want to get the value of a port (Port C) every 5 ms and save the value in memory ...
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2answers
303 views

What's the advantage of DMA in byte I/O?

I have a A/D where signals CPU(Analog Devices Blackfin 706) whenever it has new sample, and CPU reads that through a SPI, which is few bytes. Then waits for new smaple signal again. My question is, ...
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2answers
481 views

STM32 DMA short data burst buffer speed limitation

I had gone through few texts on this topic (listed below), but was not able to figure out the speed limitation of STM32´s DMA. What is needed: Take 8bit parallel burst input from external ADC (20 kB ...
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1answer
3k views

HAL + DMA + UART = STM32 crash

I'm currently working on a project which involves communication between a STM32F303RE (Nucleo board) and a classic GSM/GPS SIM808 module plus other peripherals. I want to use the DMA + UART of the ...
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1answer
280 views

PWM over DMA on STM32F100 behaves strange

I try to drive WS2812B LEDs with the STM32F100 chip. I read a lot of sources and stopped on the following thing. I have a repository with latest version of code: https://bitbucket.org/ruslanpopov/...
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1answer
778 views

STM32 SPI DMA timings between data frames and multiple DMA profiles

I'm trying to setup the STM32L432 MCU for SPI communication (24 MHz, 16 bit data size, master transmit only), using DMA. The slave device is a 32 channel amplifier chip. I need to send a specific ...
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2answers
9k views

STM32 DMA: continuous peripheral to memory (array) transfer

I am trying to use a DMA in circular mode to transfer data from an ADC to an array that will hold the data. I need to concurrently use the incoming data (in this case, I am using AT commands to send ...
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0answers
2k views

STM32 - [DMA] sine table memory to TIM->CCRx

I use STM32F031 board and i'm quite a beginner. I want to copy values from sine table directly into TIM->CCRx peripheral. I use 2 timers, one for generating PWM and the other as output capture for ...