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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

Introduction

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.

Overview

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

Resources

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

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
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
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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