diff -r 578be2adaf3e -r 307f4279f433 Adaptation/GUID-6873E764-4132-46C8-8444-6301CF4D2033.dita --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Adaptation/GUID-6873E764-4132-46C8-8444-6301CF4D2033.dita Fri Oct 15 14:32:18 2010 +0100 @@ -0,0 +1,68 @@ + + + + + +DMA Hardware InterfaceDescribes the interface between the DMA hardware and the +DMA platform service. +
Introduction

This document describes the functionality that the DMA hardware +has to provide in order to be compliant with the DMA platform service.

+
Interface +limitations

None

+
Adaptation +dependencies

Dependent on the Application Specific Standard +Product (ASSP) chip that is being used.

+
The +interface

In order to use the DMA platform service, the +following information is required:

    +
  • The location of the data source.

  • +
  • The location of the data destination.

  • +
  • The channel to be used.

  • +
  • The amount of data to be transferred.

  • +
  • How much data is to be transferred at once (packet size).

  • +
  • Synchronization setup

  • +
  • Interrupt settings

  • +

How the above settings relate to the operation of the DMA +is shown in the diagram below:

+DMA settings + +

The settings listed above will now be discussed in more detail.

Location of the data source

This specifies where +data is to be transferred from (the source). This can be one of the +following:

    +
  • Memory

  • +
  • Peripheral

  • +

If the source location is a peripheral, then its port will +have to be specified along with the location of the data source.

Location of the data destination

This specifies the +final location of the data to be transferred (the destination). As +with the location of the data source, this can be one of the following:

    +
  • Memory

  • +
  • Peripheral

  • +

If the destination is to be a peripheral, then the port configuration +will have to be specified along with the location of the destination.

Channel

The DMA platform service transfers data over +channels which are configured independently. The priority order of +the each channel is specified in the DMA platform service API.

Amount of data to be transferred

This setting specifies +the amount of data that is to be transferred from the source to the +destination.

Data packet size

Data is transferred +in packets of a specified size. The acceptable values are:

    +
  • 4 bytes

  • +
  • 8 bytes

  • +
  • 16 bytes

  • +
  • 32 bytes

  • +
  • 64 bytes

  • +
  • 128 bytes

  • +

Synchronization settings

These specify how the +transfer between the source and destination is to be controlled. This +is used when either the source or the destination can only take part +in a data transfer depending on external events. The synchronization +can be set up to be one of the following:

    +
  • No synchronized transfer

  • +
  • Synchronize the transfer after a preset number of bytes

  • +

Interrupt settings

These are used to specify +how the DMA and/or specific channels should react to interrupt events.

+
\ No newline at end of file