Point to multiple point data allocation DMA controller realization method

Abstract

The invention discloses a point-to-multipoint data distribution DMA controller realizing method which includes the following steps: (1) a DMA reading port is established, date is read into a DMA internal buffer from the external data space, and multiple DMA reading-transmission processes can be realized by allocating the descriptors of the DMA reading port; (2) a plurality of DMA writing ports are established and each writing port is corresponding to an application interface thereof; (3) different descriptors are allocated for the DMA writing ports, and data customizing is realized by controlling the destination address adding means of the writing ports and shielding the writing operation to special addresses; (4) a state machine is established to realize unified control to the reading port descriptors of the DMA controller, the descriptor loading of each writing port and the start and stop of the DMA; after the reading cycle of the reading port ends, the bus writing cycles of all the writing ports are started instantly and then an external writing sequence is generated correspondingly according to the descriptors of the writing ports so as to realize the point-to-multipoint data synchronous forwarding.

Description

1. Technical field [0001] The invention relates to a realization method of synchronously forwarding and customizing data from one source port to multiple target ports. The data source has strict requirements on the response speed of point-to-multipoint data distribution, such as realizing data multipoint forwarding and customized applications in Gigabit Ethernet data switching equipment. Specifically, the present invention relates to a realization method of a point-to-multipoint data distribution DMA (direct memory access mode) controller. 2. Background technology [0002] In the design of real-time data distribution system, in order to effectively share data and improve the response speed of the system, it is necessary to synchronously forward the same data source to different application interfaces according to different application requirements and complete data customization at the same time. [0003] At present, the existing point-to-multipoint data distribution method...

AI Technical Summary

Problems solved by technology

[0005] 1. MCU has to perform a large number of loop operations, table lookup and comparison operations when processing data movement, so the efficiency is relatively low, and when using MCU to process data distribution tasks, multiple application interfaces cannot be guaranteed to be processed concurrently, and can only be processed serially

In order to meet the real-time performance, the MCU needs to have a high main frequency and bandwidth, and increasing the main frequency and bandwidth means increasing the system cost

[0006] 2. SGDMA or linked list DMA can realize simple data allocation from one source to multiple targets, but cannot mask and filter specific data elements, and its data allocation strategy is serially performed from one port to another , there is no guarantee that data will be written synchronously to multiple applications

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