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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STM32F0 UART + DMA + Interrupt with STM32CubeMX HAL 1.2.1 problem

Hello fellow electronics engineers! I'm having a bit of a problem with setting up the STM32F072-Nucleo board as a small shell (I want to send commands via UART and set/get various settings of the ...
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238 views

Setting up T2080 to FPGA PCie DMA

I'm doing an FPGA design using a T2080 MPC interfacing to an Altera Cyclone V FPGA. The goal is to use my FPGA to pump 2 other FPGAs on the same board. I need to create a scheme that allows the ...
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1answer
3k views

MM2S simple transfer gone wrong

I followed some examples and I already managed to make a big S2MM (stream to memory-mapped) transfer via an AXI DMA. However, now I'm trying the reverse, i.e. to make a simple MM2S transfer to a very ...
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1answer
2k views

DMA on Cortex M4 for continuous UART transfer

I've never used a DMA before and I'm reading the datasheet for the Atmel SAM 4E This question does not necessarily have to pertain to this device, it can apply to any device that supports DMA if they ...
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1answer
697 views

STM32 and SDCard: space management

My task is to gather measurement from peripheries of STM32F4 on SDCard and I started reading about this. Could you double check if I'm correct: Single block memory on my SDCard is 512 bytes, so ...
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1answer
521 views

What's the difference between dual-address and implicit DMA?

For detached DMA's there are two addressing approaches. One is dual-address and one is implicit. What the difference between the two and why does dual-address take twice as many bus cycles?
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2answers
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STM32F4 - counting DMA wraps

I am using DMA on an STM32F4 Discovery board to push values from an array into a peripheral. This needs to be done repeatedly, so I am using the circular DMA mode: ...
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1answer
1k views

STM32F4 - DMA with bigger steps

I'm programming an STM32F4 Discovery board to push a sequence of 12 bit values into the DAC data register. This works well using timer interrupts: inside my IRQ handler, I have code that looks like: <...
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1answer
231 views

Is there a stride setting for PIC32MX DMA?

I'm reading the registers in the user guide for the DMA and I don't see one, but I wanted to make sure. I was hoping that in addition to cell size there was a stride size as well. So for instance ...
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1answer
869 views

Cannot change DMA configuration after first transfer

I'm using a stm32f10x microcontroller and I'm trying to program its DMA module for normal mode transfers. The first transfer works perfectly, but after it's over, I try to change the source, ...
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1answer
6k views

DMA between GPIO and SRAM on STM32

Here I am trying to move the data at the SRAM location 0x20000010 into the ODR register of ...
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1answer
127 views

Destination address of 82C37A DMA Controller

How do I select the destination address for the 82C37A DMA controller? I have gone through all the material on the web and they say that the Base Address and Current Address register contains the ...
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2answers
14k views

STM32 USART with DMA — which interrupts to use?

I'm working on firmware for an STM32F103 which is communicating over RS232 at 115200 baud with a motor controller. The motor controller (a Copley Xenus XTL) operates on a "speak when spoken to" ...
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3answers
7k views

STM32 SPI half duplex (1-wire Bidirectional) problem

Update: see my answer for fix. I'm trying to read 4 byte from a SPI-compatible slave (MAX31855) in 1-wire bidirectonal SPI half-duplex. Here is my code [SW Controlled SS] [SO->MOSI] ...
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2answers
7k views

Full duplex SPI Master using DMA - STM32F105

I'm trying to write a SPI driver for an STM32F105 using DMA functionality. I'm using ST's Standard Peripheral Library. I'm not using interrupts. I can talk to the destination device if I use standard ...
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3answers
4k views

STM32 SPI w/ DMA “BUSY” flag set

My software appears to be working as expected, but the BSY flag is not clearing in the SPI register. Background: I am trying to get SPI working with DMA on the STM32. After figuring out that the DMA ...
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1answer
457 views

dsPIC33EP DMA configuration issue

I am trying to buffer 8192 words of data from an IO Port to RAM using DMA hardware of dsPIC33EP512GM710. I have configured the interrupt source INT0 as the source for the DMA hardware. I am using ...
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1answer
2k views

DMA completion interrupt not working for slave STM32 SPI

I am using stm32f103 to transmit some data over SPI while stm32 acts as slave. I need to use DMA for sending data to the SPI but the corresponding interrupt handler is never called. The ...
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1answer
5k views

Why does last data of I2C DMA transfer break?

I used DMA to transfer I2C data, but I always lose the last data. hardware configuration is shown below: ...