javax.realtime.device

Class DirectMemoryRegion

java.lang.Object

javax.realtime.device.DirectMemoryRegion

public class DirectMemoryRegion
extends java.lang.Object

Defines the reachable memory for a given DMA controller in terms of the physical address space of the system.

Since:

RTSJ 2.0

Constructor Summary

Constructors

Constructor and Description
DirectMemoryRegion(long start, long size) Creates a DMA memory definition.

Method Summary

Modifier and Type	Method and Description
long	physicalAddressOf(long address) Translates a DMA space address into a physical address.
long	regionAddressOf(long address) Translates a physical address into a DMA region address.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DirectMemoryRegion

public DirectMemoryRegion(long start,
                          long size)
                   throws StaticIllegalArgumentException

Creates a DMA memory definition.

Parameters:

start - The DMA address space in the physical address space of the main processor.

size - The number of bytes in the DMA address space.

Throws:

StaticIllegalArgumentException - when start is less than zero or start + size is larger than the physical memory of the system.

Method Detail

regionAddressOf

public long regionAddressOf(long address)
                     throws StaticIllegalArgumentException

Translates a physical address into a DMA region address.

Parameters:

address - The address to translate.

Returns:

the equivalent address in DMA space.

Throws:

StaticIllegalArgumentException - when the result is outside the DMA space.

physicalAddressOf

public long physicalAddressOf(long address)
                       throws StaticIllegalArgumentException

Translates a DMA space address into a physical address.

Parameters:

address - The address to translate.

Returns:

the corresponding physical address.

Throws:

StaticIllegalArgumentException - when the input is outside the DMA space.