Ethernet MAC (Media Access Control) sublayer controller applicable to WLAN (Wireless Local Area Network)

Abstract

The invention discloses an Ethernet MAC (Media Access Control) sublayer controller applicable to WLAN (Wireless Local Area Network). The Ethernet MAC sublayer controller comprises a transmitter module, a receiver module, a state module, a control module, an MII (Media Independent Interface) management module, a transmission cache, a receiving cache and a register module, wherein the transmission cache and the receiving cache can realize storage, retransmission and discard of data frames by employing the asynchronous FIFO (First-in First-out) capable of loading read addresses, the information interaction of data frames between a host and the MAC sublayer controller is carried out through data frame cache descriptors which include transmitting cache descriptors and receiving cache descriptors, wherein the transmitting cache descriptors are used for controlling the transmitting process of the data frames, recording and returning a transmitting state; the receiving cache descriptors are used for controlling the reading of received data frames and returning a frame receiving state to the host. By the Ethernet MAC sublayer controller, the network access of embedded devices, the frame conflict retransmission and discard of bad frames are realized, and the utilization rate of cache in a chip is improved when short frames are received.

Description

technical field [0001] The invention relates to the MAC sublayer in the field of computer networks and the field of ASIC design in the field of microelectronics. In particular, it relates to an Ethernet MAC sublayer controller based on the IEEE802.3 standard specification, which is suitable for network access of a WLAN wireless transmission system. Background technique [0002] With the development of the Internet and electronic technology, more and more electronic devices are connected to the network. It is of great practical significance to study convenient and fast network access solutions. The IEEE802.3 Fast Ethernet standard stipulates the 10M / 100M Ethernet physical layer and MAC sublayer specifications. The protocol specification supports up to 100Mbps reliable full-duplex data transmission, which can meet the throughput requirements of most data stream transmissions. [0003] The Media Media Access Control (MAC) sublayer is in the second layer of the IEEE 802 networ...

AI Technical Summary

Problems solved by technology

The design of this cache scheme is relatively simple, but there is a problem that the frame cache utilization rate is not high when receiving short frames. For example, a minimum frame of 64 bytes also occupies a fragment (256 bytes) of cache space

If FIFO is used as the cache, there will be no waste of storage due to storage fragmentation, but the traditional FIFO read and write pointers are all sequentially increased, which is difficult to meet the function of sending data frame collision retransmission and directly discarding bad frames when receiving frames

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