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).

Filter by
Sorted by
Tagged with
0
votes
1answer
21 views

Recieving and processsing array of data on STM32

I am trying to use RealTerm to send a .txt file containing a 10X10 array of data to my STM32 NUCLEO board using UART. So far I have been using HAL_UART_Receive_DMA and I have been able to store simple ...
0
votes
1answer
40 views

How does cache coherency and DMA work together?

I am currently reading about caches and how they are used in Computer Science. The explanation of how the cache is always up to date with the actual memory is understandable as long writing and ...
0
votes
0answers
31 views

DMA + ADC + FreeRTOS in STM32 - Cannot read any ADC value - Why?

I'm using Nucleo STM32F401RE board. I have a small issue. I have connected SPI connections + two potentiometers and FreeRTOS. But I can't read the ADCs. I wonder why? I have created an array called <...
1
vote
1answer
42 views

STM32G474 signal generation with DMA + DAC using STM32CubeMX HAL

I am trying to generate a periodic signal with the DAC on the STM32G474 using DMA. There are tons of examples of this, and I´ve done the same in the past with an STM32L4 and F4 with no issues. However,...
1
vote
0answers
58 views

DMA SPI performance

I am currently writing an SD card driver for a Microcontroller using SPI and DMA. The SPI has a FIFO that can store 4 data values from the data register which has the capable of storing 32 bit. But it ...
1
vote
2answers
70 views

STM32F051 ADC DMA overrun

I am trying to use ADC with 2 channels and DMA, but I only get 1 reading before the overrun bit gets set. Also the 1 reading is wrong, I am expecting a value of approx 2100, but I am getting around 70....
0
votes
1answer
42 views

DMA Continuous Request functionality

What is the difference between these features on STM32G0 "Scan Conversion mode" and "Continuous conversion mode" and "DMA continuous request" features? When you go on CubeIDE you will see these ...
0
votes
1answer
66 views

1V on ADC pin with DMA continuous requests

I have a STM32G071 Nucleo Board and also the IC itself. In CubeIDE, I set a pin as ADC and activate DMA and enable the DMA continuous request in the ADC settings. After executing the code and ...
0
votes
2answers
60 views

UART Reception + DMA

When I am learning about DMA, I came to know that it can be implemented in UART peripheral operations too. Till now, I have used UART peripheral for simple communication operations. Sometimes I use it ...
0
votes
1answer
26 views

Decoupling setting of specific bits (transfer mode, stream, channel) from the generic DMA_Init() function

So with regards to DMA drivers, what's the approach for configuring certain bits generic inside a function which could be reused for both TX and RX calls which would require different stream parameter ...
1
vote
0answers
47 views

9*Help debug DMA TX bytes to UART

So I'm writing drivers for DMA for transmission for now and running into a few issues. So I am transferring bytes from memory to UART peripheral with a threshold of ...
0
votes
1answer
76 views

STM32 Spi receive problem

I'm trying to do simple SPI communication on STM32 Discovery, HAL lib is used. I'm trying to send some data via SPI1 and to receive same data on SPI3 (SPI1 = Full Duplex Master, SPI3 = Full Duplex ...
0
votes
1answer
69 views

How to access the other half of the DMA?

I am just trying to access the second half of the DMA. I have the half complete flag enable and working, however I am not entirely sure how to access the second half of the buffer. What I thought ...
0
votes
1answer
32 views

UART DMA RX buffer queue are being shifted on every power on- off

There is a communication between TFT NX8048p070-011r and my STM3F4 over UART. TFT sends 8byte data continuously and MCU receives by using circular DMA. I apply a parser to those data in Txclptcallback....
1
vote
1answer
43 views

Single Channel ADC with DMA giving garbage results on STM32F7

I'm looking to implement ADC and DMA with HAL on a F767. I want the ADC to be always converting and storing to memory via DMA until it reaches the buffer limit of 320 and then I want to go to a ...
0
votes
0answers
37 views

STM32 DMA BUFFER USAGE

I am using DMA for ADC and UART on my project and ADC has higher priority than USART. The ADC handles joystick and the UART handles keyboard. The ADC has 2 byte buffer and the USART has one byte ...
0
votes
0answers
25 views

I2S DMA interrupt gets fired but no data is available

I'm trying to read the I2S stream between a Raspberry Pi and a Hifiberry DAC with a STM32G071 and was able to implement the I2S DMA with the associated interrupt (or at least I think so). But ...
0
votes
0answers
104 views

AXI STREAM FIFO VHDL Implementation

Is this a right implementation of an axi stream fifo? ...
0
votes
0answers
54 views

Capture GPIO pin values with STMA32 and DMA

I am trying to capture all GPIO_C port pin values at a time when PA0 pin goes low. I am using STM32F091RC micro-controller. But I cant figure out why ...
0
votes
0answers
21 views

ADC / DMA only triggers once before setting OVR high STM32F446

I am trying to poll a block of sensors and load the data into an array via the DMA but the ADC polls only the first pin and then stops polling and sets the overrun flag high. I have implemented all ...
0
votes
0answers
29 views

STM32 ADC read temperature channel rarely between timer triggered conversions of regular channel

I am using a timer to trigger conversions of the ADC. The DMA writes the conversion results to a buffer of 512 uint16_t. When the buffer is full, an interrupt is triggered and I restart the conversion ...
2
votes
0answers
39 views

How do CPU, IOMMU and DMA controller interact with each other?

While drawing an interaction diagram involving CPU, IOMMU and DMA controller, I failed to find any authentic document showing how they interact with each other. Is the DMA controller physically a ...
0
votes
0answers
35 views

Order of disabling in `HAL_TIM_IC_Stop_DMA` function -STM32 HAL library-

Here is the function body of HAL_TIM_IC_Stop_DMA: ...
0
votes
0answers
174 views

STM32 ADC over DMA Continuous Mode Too Greedy

I am trying to read ADC data via DMA on an STM32F412. The reading itself works fine but the rest of the program is not executed anymore so it's killed by the watchdog soon. I have an array of size 50 ...
0
votes
1answer
108 views

stm32f1xx how to use DMA to write to TIMx CCR

I am trying to control WS2812b digital LEDs with stm32f103. I have a buffer of color values for the LED strip and to transfer them I need to write the next value to the timer's CCR every time the ...
0
votes
1answer
71 views

STM DMA won't continuously transmit on UART line

I am using an STM32L4R5 board and am trying to configure the DMA on the UART2 line. I have managed to get the RX line to operate how I want, but when I follow "Transmission Using DMA" in section 44.5....
0
votes
0answers
26 views

Sending Out Incoming SPI Data Through UART- PICMX250128B

I am trying to send out data(via UART) I receive from a 24-bit external ADC chip(via SPI), the ADC notifies the PIC 32 when data is ready so I am using an external interrupt handler(EXT INT). The ADC (...
1
vote
1answer
379 views

stm32 which timer and DMA channel should I use?

I am trying to control two lines of digital LEDs (WS2812b) with my STM32F103 using Timers with DMA and PWM. LED strips data lines are connected to PB5 and ...
0
votes
2answers
375 views

How to invert PWM signal on STM32

I am trying to control a WS2812 LED with STM32F103. The LED is a digital RGB LED also known as Neopixel. They are controlled by sending 24 bits of color data per LED to the first LED's data pin. The ...
0
votes
1answer
213 views

STM32F103 ADC via DMA - sequence scan to RAM can't make it work as expected

I'm using an STM32F103C8T6 BluePill board and CubeMX generated init code (Low-level libs) to setup the ADC + DMA to sequentially scan though 8 channels and write to an array in RAM. However, it either ...
1
vote
1answer
94 views

STM32 UART: combining interrupt and DMA modes

I am trying to use UART3 of STM32F103K8 to rx data in interrupt mode and tx in DMA mode. Reception works well, but transmission ...
0
votes
1answer
84 views

STM32F407 Discovery Board DCMI to SPI Output [closed]

I am currently attempting to use a STM32F407 Discovery board to display images captured with a OV2640 CMOS detector on a ILI9341 2.2" TFT SPI LCD. My goal right now is to take a single snapshot and ...
2
votes
1answer
300 views

STM32F303 ADC+DMA Averaging of measurements

What is the best method of taking multiple measurements using ADC+DMA interrupts and averaging them? Currently I have an STM32F303 with ADC2 initialized with channels 3 and 18 (Vrefint). My aim is to ...
0
votes
1answer
68 views

Memory Boundaries in SRAM

I am trying to use the GPDMA which is present in LPC43XX parts. The UM10503 data sheet constantly warns about memory boundaries (datasheet section 21): basically it says that you don't want to try a ...
1
vote
1answer
49 views

M2P DMA transfer with trigger from a different peripheral

The microcontroller on my board is STM32F429IGT6 and I want to use a timer as a trigger of a DMA -e.g. HTIM_SOUND_SAMPLER- and transfer my data from an array to CCP of another timer -e.g. ...
0
votes
1answer
76 views

Multi-channels DMA Subsystem for PCI Express

Say i have a PCIe Gen2 x4 link running in a DMA subsystem. May I know when do we need multi-channels DMA configuration? For example, FPGA vendor like Xilinx offer up to 4-read & 4-write data ...
2
votes
1answer
497 views

Why is DMA Continuous Requests not selectable as enable for STM32F446RE?

I have an Nucleo STM32F446RE and I'm used to enable DMA Continuous Requests with ADC. But in this case, I can only select disable. Why? If it's not possible to use DMA Continuous Requests with ADC. ...
1
vote
0answers
79 views

AXI4-Stream TVALID stuck low between VDMA and video output block

I'm trying to buffer a single frame of video using a VDMA block on a Trenz TE0712 board (artix-7 based development board), based on a few examples (specifically Numato's framebuffer example and Xilinx'...
2
votes
1answer
201 views

STM32 - 2 MegaByte DMA Transfer ADC To SDRAM

I want to transfer 2 MB of converted ADC data into SDRAM. I'm using STM32F429 Discovery board which is shipped with a 4-bank SDRAM (1 Meg Bits x 16 Bits x 4 Banks (64-MBIT)). I've configured the ADC ...
0
votes
1answer
176 views

Atmel SAMD21 DMA Transfer Complete Interrupt not firing

I have configured the SAMD21 peripherals so that incoming audio data from I2S will be copied into a memory buffer with DMA. As the controller allows linked DMA descriptors, I have two descriptors ...
3
votes
1answer
154 views

Why does DMA send the first byte as soon as it is enabled?

I'm using DMA to send data to GPIOF which is configured as a parallel bus. DMA is being driven by update events on TIM8. TIM8 is configured in slave mode and starts on an output compare event from ...
0
votes
0answers
124 views

Interfacing DCMI with SDIO and FMC on STM32F446VE

I am attempting to implement a system which involves capturing 1080p images via a camera connected over 8 bit parallel DCMI and saving them to an SD card via SDIO. If I understand correctly I cannot ...
0
votes
1answer
350 views

DMA, Interrupt and UART connection in STM32 for detecting chararcters

I am trying to make a project and am planning to use DMA for my UART from one STM32 to another STM32. Here are some details of what am I using: Chip: STM32F107RB debugger and programmer: Atollic for ...
0
votes
2answers
193 views

How does the DMA know “when to send” the next byte?

I'm transferring data from memory to a peripherial's register in an STM32 uC. For example take 20 bytes. I understand that after sending all the 20 bytes, the "Transfer Complete" interrupt will occur. ...
0
votes
1answer
29 views

MultiByte data integrity with DMA on STM32F3

Despite low-pass hardware filters on ADC inputs I am having a lot of erratic readings. There are 8 single-ended channels in DMA sequence and it is configured for cyclic sampling. Sampling time is set ...
5
votes
5answers
599 views

Processing ADC conversion result: DMA vs Processor Registers

I have a periodic ADC conversion (every 50 micro-seconds) and I use the result to do some further calculations and update the PWM load registers. The ADC is triggered by the up-down counter of ...
0
votes
0answers
117 views

DMA and Instruction Pipeline

My university resources say that DMA transfers the bunch of data from IO unit to memory or vice verse when processor is not busy with data and address bus. According to the resources, DMA Controller ...
3
votes
2answers
4k views

How to configure DMA to receive variable length USART messages?

I am trying to receive USART messages on a microcontroller originating from PC which will command it to execute certain tests. I am using STM32F4, I chose to use DMA as messages on the same USART ...
0
votes
1answer
130 views

CS43L22 DMA constant beep noise

I am using CS43L22 with STM32F4 discovery board. I generate sounds by sending I2S messages to CS43L22 using circular DMA buffer (32 size array). However, chip creates a constant beep whether it's ...
0
votes
1answer
45 views

DMA Init code for ADC sampled data

I am trying to figure out how this DMA Initialization code is used to sample following 4 ADC channels and save data in 'adc_data'. ...