AFDX switch data bus structure based on Crossbar architecture and data exchange method

Abstract

The invention provides an AFDX switch specific to a shared storage way, and specifically provides an AFDX switch data bus structure based on Crossbar architecture and a data exchange method specific to the aims of increasing the storage and forwarding rates of internal data of a switch, shortening time by which data frames pass through the switch and ensuring the service quality of an AFDX switch. Under the situation of not changing a scheduling algorithm, the Crossbar architecture is adopted in cooperation with separation of an original integral memory and one-to-one correspondence with bus masters, so that each bus master can access any bus slave, namely, each master can construct a data path with each switch port. The bus slaves are connected with receiving and transmitting caches of each port, and the operation is initiated through the bus masters in order to complete reading or writing of the caches. The storage and forwarding rates are higher when the quantity of the memories is larger, so that parallel transmission of data of a plurality of ports is realized.

Description

technical field [0001] The invention relates to an AFDX switch data bus and a method for storing and forwarding internal data of the switch, in particular to an AFDX switch data bus structure and a data exchange method based on a Crossbar architecture. Background technique [0002] At present, the AFDX switch widely uses the switching method of shared storage to realize the switching function of its data frame, and the data bus is an important part connecting the switch port and the shared storage. At present, there is only one shared memory in AFDX switches based on shared memory. The data bus realizes the connection between the shared memory and each port, and the data frames of each port are stored or forwarded in this unique memory. [0003] A data bus structure of AFDX switches based on Wishbone bus (Wang Binwen. Research and implementation of some key technologies of aviation full-duplex Ethernet switches [D]. Xi'an: Xidian University, 2008.) adopts the mode of one mas...

AI Technical Summary

Problems solved by technology

The main defect of this scheme is: only one pair of master device and slave device are allowed to communicate through the bus at any one time, that is, only one port data can be stored or forwarded at the same time, thus limiting the internal data storage and forwarding capacity of the switch. rate

The main defect of this scheme is: the bit width of the data bus is too large (512 bits), and there are too many data bus control signals, which will easily cause difficulties in subsequent layout and wiring, and will also affect the overall reliability of the system.

The main disadvantages of this solution are: the hardware consumption is relatively large, and a switch with N ports needs N blocks of memory and 2N DMAs; the traditional scheduling algorithm has been changed, so the data bus structure is more complicated

In the AFDX switch based on the shared storage method, without changing the scheduling algorithm, the scheme of improving the data storage and forwarding rate of the switch by improving the data bus structure, considering the cost and engineering practicability, still has certain defects, and it is feasible poor

Images