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Using the DMA controller included in the MSP-EXP430FG4618 Development Tool analysed the data transfer between two regions of memory.

Laboratory dma: lab1 - data memory transfer triggered by software


This laboratory gives an example of the use of the DMA peripheral available in the MSP-EXP430FG4618 Development Tool. It requires the configuration of the DMA Source and Destination Addresses Registers, DMA Size Address Register; DMA Control Registers and DMA Channel 0 Control Register in order to transfer data between two regions of memory.


During this laboratory ( Lab1_DMA.c ), the data transfer between two regions of memory is analyzed. The order of transfer is controlled by software.


The following resource is used in this laboratory:

- DMA controller.

Software application organization

The software begins by disabling the watchdog timer. Port P2.1 is set as an output with a logic low level.

The memory addresses of the data vectors are passed to the source data address DMA0SA and destination address DMA0DA registers.

The number of words to be transferred is loaded in the DMA0SZ (size) register.

The DMA channel 0 is configured so that the data transfer trigger is controlled by software, in order that after each transfer, the source and destination addresses are correctly incremented.

The application enters an infinite loop, where port P2.1 state is switched just before initiating the data transfer.

System configuration

Dma channel configuration:

The source address and destination address of the data must be loaded into their respective registers:

DMA0SA = (void (*)( ))&tab_1; // Start block addressDMA0DA = (void (*)( ))&tab_2; // Destination block address

To move a total of 32 words, what is the value to write to the data size register?

DMA0SZ = 0x0020; // Block size

The DMA channel must be configured to transfer the word under software control. The source and destination addresses should be incremented immediately after each of the transfers.

DMA0CTL=DMADT_0 | DMASRCINCR_3 | DMADSTINCR_3 | DMAEN; // Single transfer,// DMA source and destination addresses increment, // Enable DMA0

Analysis of operation

In the Memory window, the addresses of data vector Tab_1 and Tab_2 addresses are displayed. The contents of these blocks must be identified in memory.

Add a breakpoint at line of code that performs the switching of port P2.1 state.

Execute the application, and whenever the breakpoint is reached, the execution of the application will be suspended. Observe the data being gradually transferred from source to destination.

The data transfer is suspended once the 32 elements of the source data vector have been transferred.

This example and many others are available on the MSP430 Teaching ROM.

Request this ROM, and our other Teaching Materials here (External Link)

Questions & Answers

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Crow Reply
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RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
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Brian Reply
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industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
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scanning tunneling microscope
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what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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Stoney Reply
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Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
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Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
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Source:  OpenStax, Teaching and classroom laboratories based on the “ez430” and "experimenter's board" msp430 microcontroller platforms and code composer essentials. OpenStax CNX. May 19, 2009 Download for free at http://cnx.org/content/col10706/1.3
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