Data caching architecture applied in local side of Ethernet passive optical network (EPON) system

Abstract

The invention discloses a data caching architecture applied in a local side of an Ethernet passive optical network (EPON) system, which provides a flexible data caching architecture by the following steps of combining an external synchronous dynamic random access memory (SDRAM) and an internal static random access memory (SRAM); adopting flexible dynamic adaptation data service grades; and utilizing a strategy capable of allocating the cache capacity for each service grade, and partioning the data caching into multiple blocks through using a certain byte as a unit. The data caching architecture is applied in the chip development process of an optical line terminal (OLT), and has satisfied effect and high bandwidth utilization rate after actual operation tests, and can meet the EPON system data transmission requirements; and proven by the tests, the uplink total bandwidth can reach no less than 980Mbps when the random length of a frame is transmitted and the frame is portioned into 8 service priority grades.

Description

technical field [0001] The present invention relates to a data cache architecture applied in EPON central office system (OLT), which uses the combination of external SDRAM and internal SRAM to cache data, and can dynamically configure whether to distinguish the service level of data to allocate corresponding cache capacity. Background technique [0002] The EPON system is a point-to-multipoint network system, which mainly includes three parts: central office OLT, terminal ONU and passive optical splitter, as attached figure 1 shown. In the downstream direction, the Ethernet data packets sent by the OLT are transmitted to each ONU through a 1xN passive optical splitter in a broadcast manner, and the ONUs selectively extract the data packets; Due to the directional characteristics of the splitter, the data packets sent by any ONU can only reach the OLT, but not the ONU, that is, the data of all ONUs are transmitted to the same OLT, thus constructing the point-to-multipoint n...

AI Technical Summary

Problems solved by technology

[0005] First, when using a fixed space configuration to cache data, the cache space must be allocated according to the service levels that may appear in the data, and it must be able to handle any service level, which requires a lot of cache space. At the same time, when the data When service levels are not distinguished or only a few but not all service levels appear, the cache space is wasted and the utilization rate is low;

[0006] Second, in terms of data cache management, since the data is completely stored in the memory, in order to be able to read and write well, the additional information of the data is generally written into the cache together with the data. When reading the data, first read the additional information of the data, and then read the data, which will reduce the efficiency of data reading and writing.

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