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microchip公司的OS81110是用于车内网络接口标准(MOST)的智能网络接口控制器,数据速率150Mbps,其智能网络接口控制器(INIC)架构能从现在的MOST无缝地升级到MOST150, 也能用于MOST25和MOST50的应用.工作电压1.8 V/3.3 V.本文介绍了OS81110主要特性和硬件框图, MOST150视频演示框图, OS81110 cPHY评估板主要特性和框图与应用框图,电路图,PCB元件布局图和PCB顶层与底层走线图. The OS81110 is a new Network Interface Controller that supports MOST (Media Oriented Systems Transport) data transport at 150 Mbits/s. The chip has been architected to enable a seamless migration of existing MOST applications and systems to MOST150. It uses SMSC’s familiar Intelligent Network Interface Controller (INIC) architecture, also used for MOST25 and MOST50 applications. It fully encapsulates the network interface functions and can also operate as a stand-alone solution. The OS81110 uses the same INIC API for the legacy features, which allows existing application software including the NetServices driver stack to be migrated to MOST150 with minimal required changes. The chip supports a low-cost LED/POF-based optical fiber physical layer. Since existing optical wire harnesses and connectors can be used without modification, the migration to MOST150 is straight forward.OS81110 supports legacy control, synchronous, and packet channel data formats from MOST25 and MOST50. The control channel can be used for real-time status exchange and control of devices. It runs independently from the other transport mechanisms and has its own data integrity methods. For bigger packets and data transmission with no real-time requirements, MOST provides a separate legacy embedded asynchronous packet channel.It also has its own data integrity and flow control mechanisms. The synchronous channels are completely separated from the other transport echanisms. Collisions or priority conflicts do not occur and therefore maximum Quality of Service (QoS) can be achieved. The necessary bandwidth is allocated via commands on the control channel. Once established, a synchronous channel is always available for the source of the data and one or more sinks. The signal itself can be streamed onto MOST without any need for packetizing or addressing. Unlike networks that originate in the IT world, MOST has been specifically designed to utilize bandwidth efficiently and deliver high-QoS audio and video streaming, even in a demanding automotive environment. The delay from node to node is very low and predictable. It has been reduced from that of MOST25 and is just 162 nanoseconds per timing slave node and 20.8 microseconds across the timing master device. These delays can usually be neglected but, if necessary, they can be compensated as they are predictable. Therefore, MOST150 is well-suited to help minimize echoes, wow and flutter effects in multi-room sound systems and surround sound as well as home theater systems with active speakers.In addition to supporting legacy MOST data formats, the OS81110 features two new types of data transport: The new MOST Ethernet channel allows the transport of legacy Ethernet packets and supports MAC addressing.From an application perspective, the MOST Ethernet channel behaves like Ethernet. MOST looks like Ethernet to applications that use Ethernet frames or IP, such as TCP/IP stacks. These Ethernet applications can be used on MOST without modification or an adapter layer since MOST150 is an automotive grade physical layer for Ethernet and IP communications. The new isochronous channels and clocking capabilities of the chip close the gap between synchronous and packet transport. While they are managed like synchronous streams, they make it possible to transport streams that are not synchronized to MOST and its frame rate. These streams range from PCM audio streams, which by nature are synchronous but might not have been synchronized to MOST, to bursty MPEG streams, to streams of packet data.Allocation of bandwidth between the different channels can be managed dynamically in a highly flexible manner.All MOST data types, including MOST150, are very efficient in managing bandwidth when compared to other, mostly packet-orient, networks. MOST150 can flexibly transport data and data streams that can occur in a modern infotainment system. The OS81110 provides legacy serial interfaces for all kinds of control, audio, video and packet data to support many applications at a minimum system cost. In addition to using I2C for control, the OS81110 provides an SPI for high-speed packet communication. The OS81110 also provides two dedicated Transport Stream Interfaces that carry streaming data directly to or from video SoCs. Glue logic is typically not required, which allows for highly cost effective digital audio and video solutions. To support audio applications, the OS81110 features four highspeed streaming ports that can handle various formats including SPDIF or I2S, to allow that a 7.1 channel surround sound source or amplifier can be hooked up directly to the INIC. In addition to generic interfaces, MediaLB can be used as a single serial interface for all MOST data types. The OS81110 also provides a highspeed differential mode, called MediaLB 6-Pin that delivers a data throughput of up to approximately 300 Mbits/s between INICs and other MediaLB 6-Pin implementations. |
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