GMSL Expands Beyond Automotive Applications

Vision applications demand substantial data streams to ensure high-quality video. A full HD image comprises 1080 rows by 1920 columns, totaling more than 2 million pixels. When transmitted at 60 frames per second, the raw data rate quickly climbs into the gigabit-per-second range. This is where product designers can take advantage of Gigabit Multimedia Serial Link (GMSL).

Originally developed by Maxim and now in Analog Devices, Inc.’s portfolio, GMSL continues to evolve as a leading high-speed video and data link technology. It was created for automotive high-speed video and data transmission applications and has now progressed through three generations (GMSL1, GMSL2, and GMSL3) with more than 900 million ICs shipped globally. It is undergoing a surge in adoption in a range of non-automotive applications where high-speed, low-latency video and sensor data transmission is critical:

• GMSL is used to connect machine vision cameras in robotics and inspection systems, offering reliable performance across factory floors where EMI and long cable runs can challenge conventional interfaces.
• In medical devices, GMSL enables real-time video from surgical and diagnostic cameras, especially in compact systems where minimal cabling and latency are essential.
• Aerospace and defense designers use GMSL to transmit mission-critical imaging and sensor data in aircraft, drones, and surveillance systems, benefiting from the technology’s ruggedness and diagnostics.
• Rail and public transit systems use GMSL to deliver video feeds and passenger information between vehicles and control units.

Across these industries, GMSL’s blend of bandwidth, resilience, and simplicity helps designers meet the demands of camera- and data-driven systems. While often perceived as a high-end solution, GMSL can be applied to low-volume professional builds requiring robust, high-speed video or sensor links.

Core capabilities

GMSL is a high-speed serializer/deserializer (SerDes) technology designed to carry video, audio, control, and power over a single cable—typically coaxial or shielded twisted pair (STP). GMSL supports asymmetric full-duplex communication, featuring a forward channel for high-bandwidth video transmission and a reverse channel for low-frequency control signals.

The technology supports distances up to 15 m and speeds exceeding 6 Gbps in its latest versions. These features enable GMSL to support high-resolution video, including 8 MP sensors and 4K+ displays.

Many modern applications—from automotive driver assistance to industrial machine vision—depend on real-time, high-resolution video. A full HD frame has 2 million pixels, so a pixel storing 8 bits for each red, green, and blue channel—24 bits in total—adds up to nearly 50 Mb of uncompressed data per frame.

A single uncompressed 1080p video stream at 60 frames per second can demand over 3 Gbps of bandwidth, and that’s before adding overhead for color depth, synchronization, or error correction. GMSL’s ability to transmit multiple gigabits per second over a single coaxial or STP cable allows designers to deliver crisp, low-latency video without resorting to compression schemes that increase complexity and introduce delays.

Latency is a key concern in time-sensitive applications. Whether it’s a vehicle’s forward-facing camera helping to detect hazards or a robot on an assembly line adjusting its grip, even slight delays in video transmission can degrade performance or safety.

GMSL’s high-speed links support near-instantaneous transmission of video and sensor data, making it ideal for systems that rely on real-time feedback and decision-making. That's critical for applications where latency is a concern, such as detecting hazards on an assembly line.

Another important feature of GMSL—particularly in space-constrained or cost-sensitive designs—is its support for integrated power delivery over the same cable used for data. Known as Power over Coax (PoC), this capability allows a single coaxial cable to carry video, control signals, and power to remote devices such as cameras, displays, or sensors. This reduces the need for separate power lines, cutting down on wiring complexity, weight, and cost.

PoC has been a core feature of GMSL since its first generation and is especially valuable in automotive, industrial, and embedded applications where long cable runs or flexible routing are involved. With each successive generation, PoC has evolved to support higher power levels, improved efficiency, and better EMI performance, along with enhanced diagnostics and protection features to support more complex, multi-device system designs.

Spanning GMSL generations

First-generation GMSL, initially released in 2008, utilized the low-voltage differential signaling (LVDS) standard to deliver parallel data downlink rates up to 3.125 Gbps. This standard was particularly well-suited for transmitting data from multiple camera systems and other advanced driver assistance systems (ADAS) applications, as well as the increasing adoption of in-car, high-definition flat panel displays. GMSL1 components continue to be a viable and widely available choice for product designers working on cost-sensitive or bandwidth-moderate applications, and are well-supported by GMSL2-compatible receivers.

• The MAX96705 is a compact, cost-effective GSML1 serializer with integrated PoC that supports data rates up to 1.5 Gbps, which is suitable for entry-level automotive vision systems, industrial inspection cameras, and other vision applications that don't have the bandwidth demands of GMSL2 or GMSL3.

GMSL2 utilizes a proprietary high-speed serial protocol that enables embedded clocking, enhanced EMI performance, and higher data rates—all over a single differential pair. Most notably, it doubled the available bandwidth to 6 Gbps, enabling support for higher-resolution video streams, increased frame rates, and even multiple aggregated cameras. It eliminates the need for separate clock lines, reducing wiring complexity and improving signal integrity over longer distances. GMSL2 maintains backward compatibility with GMSL1, easing the transition to more capable designs without a full platform overhaul.

• The MAX96716A is a dual-input deserializer that supports both GMSL1 and GMSL2 links and data rates up to 6 Gbps per lane, and outputs to MIPI CSI-2, a common interface for SoCs and vision processors. With built-in I²C bridging, PoC support, and forward error correction (FEC), it’s a reliable, flexible solution for multi-camera setups or for bridging older and newer serializers without having to redesign the host interface.

GMSL2 meets the stringent electromagnetic compatibility (EMC) requirements of automotive and industrial applications, where traditional LVDS often falls short. GMSL2 also added support for both uncompressed and compressed video, giving designers more flexibility depending on system constraints. Unlike GMSL1, it uses an embedded clock, reducing EMI and simplifying cable design.

Other generational improvements with GMSL2 included improved control data handling, with lower latency transmission of I²C, SPI, GPIO, and audio, along with built-in diagnostics and error detection for greater system robustness.

GMSL3 further advanced vision applications with support for aggregation, allowing several high-resolution video streams, bidirectional control signals (such as I²C, GPIO, and SPI), and audio to be transmitted over a single physical cable. This simplifies wiring and reduces weight and complexity in space-constrained designs.

In many modern applications, multiple video sources—such as cameras—and peripheral devices—like sensors or displays—must communicate simultaneously with a central processor.

GMSL3 supports data rates of up to 6 Gbps per serial lane, with configurations using multiple lanes to further increase throughput.

• The MAX96793GTJ/VY+ is a compact, GMSL3 serializer that inputs up to four lanes of MIPI CSI-2 video and outputs a single 12 Gbps GMSL3 link, with built-in backward compatibility to GMSL2 (Figure 1).

Figure 1: MAX96793 GMSL3 serializers with built-in backward compatibility to GMSL2 provide designers an efficient solution for high-resolution, multi-camera systems or upgrading from GMSL2. (Image source: Analog Devices, Inc.)

• ADI's MAX96792A is a high-performance dual-lane GMSL3/GMSL2 deserializer that can aggregate two serial lanes for a total of 12 Gbps of serialized video, control, and audio data (Figure 2). That enables multi-camera or high-resolution video capture through dual MIPI CSI-2 interfaces and provides the capabilities for advanced driver assistance systems, autonomous vehicles, advanced machine vision, and other high-bandwidth applications. Support for both GMSL3 and GMSL2 simplifies upgrades across product lines. (Operating in GMSL2 mode, it could pair with the MAX96717RGTJ/V+ GMSL2 serializer.)

Figure 2: The MAX96792A dual-lane GMSL3/GMSL2 deserializer provides capabilities for advanced vision applications. (Image source: Analog Devices, Inc.)

Designers can take advantage of evaluation boards and development kits to explore GMSL3 capabilities and prototype with real hardware.

• MAX96793-ACK-EVK# (Figure 3) with MAX96793 serializer IC allows designers to quickly prototype and test high-speed GMSL3 and GMSL2 video links, converting MIPI CSI-2 input to up to 12 Gbps GMSL3 output over coax or STP.

Figure 3: The MAX96793-ACK-EVK# provides an opportunity for prototyping GMSL3 applications with the MAX96793 serializer. (Image source: Analog Devices, Inc.)

• The MAX96792A-BCK-EVK# (Figure 4) evaluation board for the MAX96792A is a dual-lane GMSL3/GMSL2 deserializer evaluation board that demonstrates full-featured GMSL3 operation using two 6 Gbps lanes (12 Gbps total) over coax or STP via PAM-4 signaling.

Figure 4: The MAX96792A-BCK-EVK# evaluation kit includes a GSML3 deserializer for prototyping applications. (Image source: Analog Devices, Inc.)

Broad adoption and robust ecosystem

ADI’s GMSL technology has seen broad industry adoption across automotive, industrial, medical, and aerospace sectors. Its combination of high-speed video transmission, power delivery, EMI resilience, and system-level integration has made it a de facto standard for high-performance vision systems where open protocols fall short.

ADI offers a proven, scalable platform for deploying real-time video and sensor links in demanding environments, backed by a robust ecosystem of serializers, deserializers, camera modules, and development tools.

Backward compatibility is a key feature across GMSL generations. GMSL2 is backward-compatible with GMSL1 in many configurations, allowing certain serializers and deserializers designed for GMSL2 to operate in GMSL1 mode when paired with a GMSL1 device. This enables designers to scale their designs while leveraging existing hardware.

While GMSL3 uses a fundamentally different signaling protocol and higher-speed architecture, ADI offers components that operate in dual GMSL2 and GMSL3 mode. This provides designers flexibility in implementing gradual system upgrades or offering multi-platform product lines, such as a high-end GMSL3-based model and a low-end GMSL2-based model.

Conclusion

GMSL streamlines design complexity, reduces wiring, and supports the growing demand for high-bandwidth, low-latency data in embedded and edge systems. The advanced signal conditioning and error correction of GMSL ensures applications can maintain fast, high-integrity links even in harsh conditions and over distances of 15 m or more, whereas other interfaces like USB, HDMI, or MIPI CSi typically suffer signal degradation over that distance, particularly in the noisy environments found in vehicles or factories. Backward compatibility across GMSL generations ensures seamless integration of newer components into existing systems, enabling gradual upgrades without a full redesign and helping to balance cost, performance, and supply chain flexibility across product lines.