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Direct memory access (DMA) sending method

A sending method and DMA controller technology, applied in the field of communication, can solve problems such as not easy to expand, consume system resources, slow speed, etc., and achieve the effect of improving transmission and processing capabilities, ensuring determinism and real-time performance, and length optimization

Active Publication Date: 2012-04-18
CHINESE AERONAUTICAL RADIO ELECTRONICS RES INST
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The original inter-module data transmission mode (such as ARINC629 bus transmission speed of 2Mbps and 1553B bus transmission speed of 1Mbps, ARINC429 bus transmission speed of 100Kbps) has the disadvantages of slow speed, consumption of system resources and difficulty in expansion

Method used

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  • Direct memory access (DMA) sending method
  • Direct memory access (DMA) sending method
  • Direct memory access (DMA) sending method

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Embodiment Construction

[0029] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings to describe the technical solution of the present invention in detail.

[0030] To realize the definite, real-time and reliable transmission of large-capacity data in the AS5643 network, such as figure 1 As shown, according to the data flow sequence of data packets from application layer, transaction layer, link layer to physical layer, the DMA transceiver is improved and optimized from top to bottom. The following methods are applicable to both CC nodes and REMOTE nodes.

[0031] 1. Application layer packet length optimization includes the following:

[0032] In order to reduce the packet loss rate and increase the bandwidth utilization rate, the present invention optimizes the data packet length from the application layer of the sending node. The frame format of the AS5643 protocol is as follows: figure 2 As shown, assuming that the effective message le...

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Abstract

The invention discloses a direct memory access (DMA) sending method, which comprises the following steps of: 301, according to an application layer, determining the length and number of data packets which are sent in each period; 302, creating a descriptor for each data packet; 303, judging whether the descriptor is the first descriptor; 304, regarding the current descriptors as the head and tail of a new descriptor queue; 305, resetting a RUN bit in a context control register; 306, according to an active bit in the context control register, checking a result of the step 305; 307, writing the addresses of the descriptors into a link layer command pointer register; 308, setting the RUN bit in the context control register as 1; 309, judging whether sending of N data packets is finished; 310, reserving DMA sending descriptors in a centralized mode; and 311 to 314. By adoption of the DMA sending method, a plurality of data packets can be continuously sent, and transmission of high-capacity data is realized.

Description

technical field [0001] The invention relates to a communication technology, in particular to a DMA (Direct Memory Access, direct memory access) sending method. Background technique [0002] With the continuous upgrading of avionics system architecture and the rapid development of computer technology, the processing capacity of single-board computers has been greatly improved. The communication bottleneck of the system will no longer be the processing module, but the data between modules and between systems. communication bandwidth. Avionics bus technology is getting more and more attention. Some high-speed serial buses such as IEEE 1394B are being gradually applied to the design of advanced avionics systems. It has significant advantages such as high speed (up to 3.2Gbps), hot swap, point-to-point transmission, easy expansion, and long transmission distance. [0003] According to the application in the field of military and aviation transportation, on the basis of IEEE 139...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L12/56H04L12/40H04L12/861
Inventor 楼俊荣
Owner CHINESE AERONAUTICAL RADIO ELECTRONICS RES INST
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