The battle for high-definition multimedia interfaces (HDMI) and DisplayPort is quickly slamming, and HDMI is quickly and undisputedly the preferred protocol for next-generation audio/video connectivity, becoming the modern TV, media player, game console and camera. Standard features. This article refers to the address: http:// Different modes, different applications Many people now realize that both DisplayPort and HDMI provide advanced audio/video interfaces, while the main differences between them cause them to move in different directions. Learn about DisplayPort Figure 1 DisplayPort link overview DisplayPort verification and conformance testing Figure 2 Example of jitter pattern for 2MHz jitter curve calibration SC/APC Fiber Optic Fast Connector Sc/Apc Fiber Optic Fast Connector,Fiber Optic Adaptor Fast Connector,Fiber Quick Connect Kit,Sc Fiber Optic Fast Connector Ningbo Fengwei Communication Technology Co., Ltd , https://www.fengweifiberoptic.com
HDMI supports multi-channel digital audio and any TV or personal computer (PC) video format on a single cable, including standard, enhanced, and high-definition formats. This flexibility has allowed it to be adopted rapidly around the world and is expected to become an efficient and universal connection interface in the next few years.
Faced with this development momentum, why do more than 180 computer and consumer electronics companies actively support another audio/video interface standard DisplayPort? These companies include industry giants such as Hewlett-Packard, Dell, Intel and AMD, and in the past four years, this number is growing at a rate of more than 20% per year; in the face of HDMI mainstream, support for DisplayPort and The development of DisplayPort continues to thrive.
There are three possibilities for this: “war†is not over yet; there is no such thing as competition before; or any standard only needs to find its own place.
HDMI has been widely used in high definition television (HDTV) applications due to its ability to support multiple video and audio formats, and HDMI is supported by countless devices connected to HDTV. However, HDMI is not a panacea for all audio/video connections. Engineers are cautiously examining their use in PC technology, especially in high-performance PC displays, based on three distinct factors: cost, bandwidth, and internal connectivity.
The licensing fees and royalties associated with HDMI have discouraged many low-cost, high-volume technologies, such as PC monitors. HDMI's external clock limits its bandwidth and performance expansion capabilities. The focus is on the connection between consumer electronics devices, lacking internal inter-chip connections that reduce design complexity and cost.
As displays increasingly turn to higher-performance flat panel and microelectronics technologies, engineers need an economical, scalable, open, industry-standard digital interface that requires performance scalability.
The DisplayPort specification specifies an expandable digital display interface with optional audio protection and content protection for a wide range of commercial, enterprise and consumer applications. This interface design supports internal inter-chip connections and digital display connections between external devices.
As shown in Figure 1, the DisplayPort interface consists of a primary link that carries high-bandwidth data, a secondary channel used by the link and device management, and a hot-swap detection line that receives the interrupt request initiated by the device.
While providing performance, cost and design advantages, DisplayPort also brings a number of device specification conformance requirements, including clear, multifaceted transmitter (source), receiver (receiver) and cable testing.
Fortunately, DisplayPort has many similarities to established serial data technologies such as PCI-Express and Serial ATA. As a result, engineers working with the universal serial data standard in the computer electronics industry will not be unfamiliar with DisplayPort testing and compliance testing processes.
However, each segment within the DisplayPort interface has its own unique testing challenges. Since DisplayPort uses a dynamic working model, hundreds of test conditions must be examined. Like many other standards, DisplayPort has published its own conformance test standard (CTS) requirements.
Leading test and measurement providers have developed tools and methods for DisplayPort that include detailed Conformance Test Steps (MOI), which can be used as a DisplayPort source for specific test equipment under a variety of different test conditions. , cable and receiver provide verification.
DisplayPort has 17 source-side tests, 12 of which require conformance testing, including amplitude, data rate, offset, spread-spectrum clock, eye diagram test, and more. The challenge for developers is that they must examine a large number of unique working conditions in the DisplayPort source test, a total of 28 kinds.
DisplayPort has seven cable tests, five of which require conformance testing, including offset, noise, impedance, insertion loss and return loss, and other measurements. Developers must work hard to ensure measurement accuracy, especially when using de-embedding techniques. In addition, depending on the test equipment used, they must also determine if the instrument affects the measurement.
DisplayPort has only one receiver test, with a focus on jitter tolerance, but this test is particularly tricky. For "worst", but still standards-compliant signals, developers must verify that the receiver is still recovering data at an acceptable bit error rate (BER).
They must establish seven jitter curves—including random jitter, sinusoidal jitter, and inter-symbol interference (ISI) patterns to characterize jitter and test the tolerance of the device under test (DUT), as shown in Table 1. An example of the jitter pattern of the 2MHz jitter curve calibration is shown in Figure 2.
Other high-performance display standards typically perform receiver tests using dithered patterns like DisplayPort, but require the user to visually check for pixel errors. DisplayPort uses a built-in error detector to facilitate a more automated test process.
As we all know, DisplayPort testing itself is not difficult or complicated. However, due to the long time-consuming, the cost is high. Manually testing multiple test states in multiple data paths is cumbersome. This leads to non-repetitive testing, frequent human error, and rapid development costs.
By working with some test and measurement vendors, developers can significantly increase productivity and reduce and reduce the time and cost of DisplayPort compliance testing. These vendors can provide detailed step-by-step MOI and DisplayPort specific test software to eliminate manual measurements and automatically analyze DisplayPort test data. Once the DUT is set up, these software tools can automate all DisplayPort test procedures, including data processing, measurement, and analysis.
In addition, all test data is automatically saved and archived when using these software tools. This means that even without a DUT, it is easy to re-run the test, improving the repeatability of debugging, troubleshooting, and compliance testing procedures. Commonly used detailed test reports include graphs, screen shots, and test pass/fail results to improve report compilation.