blob: 3b6301e09f59715192549a968412c5e4b9ee6c90 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
|
.. SPDX-License-Identifier: CC-BY-SA-4.0
.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
.. index:: dual ported memory, definition
.. index:: external addresses, definition
.. index:: internal addresses, definition
Background
==========
A dual-ported memory area (DPMA) is an contiguous block of RAM owned by a
particular processor but which can be accessed by other processors in the
system. The owner accesses the memory using internal addresses, while other
processors must use external addresses. RTEMS defines a port as a particular
mapping of internal and external addresses.
There are two system configurations in which dual-ported memory is commonly
found. The first is tightly-coupled multiprocessor computer systems where the
dual-ported memory is shared between all nodes and is used for inter-node
communication. The second configuration is computer systems with intelligent
peripheral controllers. These controllers typically utilize the DPMA for
high-performance data transfers.
|
