提问前须知 Readme

Q1：为什么有些GMSL芯片型号无法在官网上搜索到？

Q1: Why are some GMSL chip parts not searchable on the official website?

A：目前，GMSL区分为公开器件和非公开器件，公开器件为可以在官网上直接搜索到，并且有产品主页的型号；非公开器件为官网上搜索不到的器件，若想获取相关资料及支持，必须由所在公司与ADI签订保密协议（NDA）。因此，非公开器件也无法在此论坛获得支持。

A: At present, GMSL is divided into public devices and non-public devices. Public devices are parts that can be directly searched on the official website and have a product homepage. Non-public devices are devices that are not searchable on the website, and to obtain relevant information and support, the company must enter into a non-disclosure agreement (NDA) with ADI. Therefore, non-public devices cannot be supported in this forum.

Q2：GMSL设计和配置都很复杂，有什么公开的资料可供参考？

Q2: GMSL design and configuration are very complex, what is the public information available for reference?

A：常用的有Hardware Design Guide、User Guide、Channel Specification，这些文档可在GMSL2代公开器件的产品主页下载，例如MAX96717/MAX96724等。GMSL的GUI也可以直接生成配置脚本，方便更快速地开始使用芯片，GUI软件可在公开器件的产品主页下载。非公开器件有其专用的GUI版本，获取方法见Q1。

A: Commonly used documents are Hardware Design Guide, User Guide, Channel Specification, which can be downloaded from the product home page of GMSL2 public devices, such as MAX96717/MAX96724. The GMSL GUI can also generate configuration scripts directly to make it easier to start, and the GUI software can be downloaded from the product home page of the public device. Private devices have their own version of the GUI, see Q1 to obtain.

Q3：我想在使用前对GMSL有一个基本的认识，有视频教学资料吗？

Q3: I want to have a basic understanding of GMSL before using it. Are there any video tutorials?

A: 可以查看GMSL U里面的课程：GMSL U - EngineerZone (analog.com)

A: Luckily, we launched GMSL U where exhibits some useful courses for you: GMSL U - EngineerZone (analog.com)

Q4：我们公司已经与ADI签订了NDA，也已经在使用相关器件，我该怎么获取支持？

Q4: Our company has signed an NDA with ADI and is already using related devices. How can I get support?

A：汽车相关客户一般有直接对接的FAE，如不清楚，请咨询您的同事寻找其联系方式。其他领域客户也可与ADI FAE或代理商FAE联系。

A: Automotive related customers generally have direct contact FAE. If not clear, please consult your colleagues to find their contact information. Customers in other areas can also contact ADI FAE or distributor FAE for support.

Q5：我设计了自己的硬件，该怎么判断GMSL链路质量好坏？

Q5: I have designed my own hardware. How can I evaluate the quality of GMSL link?

A：

从物理层角度，判断的标准是Channel Specification文档中对系统插入损耗IL和回波损耗RL的要求是否满足，测试方法已经在上述文档中详细描述。

如没有相关测试条件，可以通过芯片内部Eye Opening Monitor对眼图进行测试，需自行编写程序访问寄存器相关值后，在软件中绘制出来，绘制算法在GUI软件中有文档描述。

注意，不可以使用一般示波器直接测量芯片PIN处的眼图，因为芯片内部有均衡器，经过均衡器后的信号眼图与芯片PIN处的信号眼图可能存在较大差异。

From the perspective of physical layer, the criterion is whether the requirements of system insertion loss and return loss in the Channel Specification document are met, and the test methods have been described in detail in the above document.

If there is no relevant test condition, you can test the Eye map through the Eye-Opening Monitor inside the chip. You need to write your own program to access the relevant value of the registers and draw it in your software. The drawing algorithm is described in the documentation in the GUI software.

Note that you can not use a general oscilloscope to directly measure the eye map at the chip PIN, because there is an equalizer inside the chip, and the signal eye map after the equalizer and the signal eye map at the chip PIN may be greatly different.

Q6: MIPI PORT、Virtual Channel、Stream ID、GMSL Link之间的关系是什么？

Q6: What is the relationship between MIPI PORT, Virtual Channel, Stream ID and GMSL Link?

A：

这些概念不可混同。

MIPI PORT是视频流输入/输出的接口，物理层可以有DPHY和CPHY，协议层可以有CSI和DSI，物理层和协议层之间没有强制对应关系。对于CSI-2协议来说，同一MIPI视频流中可以有多个Virtual Channel，时分复用，区分不同的视频流。

Virtual Channel进入GMSL芯片后，在pipe中进行缓冲等待进入GMSL Link传输到另一侧，来自同一PORT的多个Virtual Channel可以进入到同一个pipe中。不同pipe内的数据进入到GMSL Link时，以Stream ID进行区分。单个GMSL Link可以有多个Stream同时传输。

Stream通过GMSL Link进入到解串器端，解串器端的pipe通过Stream ID选择接收哪个视频流。

These concepts are not same.

The MIPI PORT is an input/output interface for video streams. The physical layer can have a DPHY or a CPHY, and the protocol layer can be CSI or DSI. There is no fixed mapping between the physical layer and the protocol layer. For CSI-2 protocol, the same MIPI video port can have multiple Virtual Channels, time division multiplexing. They distinguish different video streams.

After the Virtual Channel enters the GMSL chip, it is buffered in the pipe to wait for the GMSL Link to be transferred to the other side. Multiple Virtual Channels from the same MIPI PORT can enter the same pipe. When data from different pipes enters the GMSL Link, it is distinguished by the Stream ID. A single GMSL Link can have multiple streams transmitted simultaneously.

The Stream passes through the GMSL Link to the deserializer, and the pipe at the deserializer selects which video Stream to receive through the Stream ID.

欢迎在此处分享相关调试经验！

It is strongly welcomed to share your design experiences here!