USB-C display vs display with USB-C – what’s the difference?

Table of Contents

USB-C is increasingly used in embedded displays, but its presence does not define functionality.

From a system design perspective, there is a critical distinction between:

• USB-C display (video over USB-C)
• display with USB-C (USB interface only, e.g. touch)

These two approaches differ in architecture, signal routing, and software requirements.

USB-C as connector vs USB-C as interface

In many embedded displays, USB-C is used only as a USB interface (for example for touchpanel handling).

In this case:

• USB-C carries USB 2.0 signals (D+ / D-)
• It is used for touch communication
• Video is handled via a separate interface (e.g. HDMI, LVDS, RGB)

This means the system still requires multiple connections.

In contrast, a true USB-C display uses USB-C as a full interface, integrating video, touch, and power.

USB-C display – signal structure

A USB-C display relies on multiple signal groups within the same connector. Based on the Riverdi USB-C display implementation, the interface includes:

• VBUS (5V power supply)
• GND (ground reference)
• SuperSpeed differential pairs (TX/RX) for high-bandwidth data
• USB 2.0 lines (D+ / D-) for touch and control
• Configuration Channel (CC1 / CC2) for role detection and negotiation
• Sideband Use (SBU1 / SBU2) used in DisplayPort Alt Mode

These signals allow simultaneous transmission of video, touch data, and power over a single cable.

Comparison – USB-C display vs HDMI + USB (touch)

Behavior on embedded MPU platforms (e.g. Toradex)

In embedded Linux environments such as Toradex platforms, the difference becomes practical:

HDMI + USB (touch)

• HDMI is handled by the GPU/display subsystem
• Display is typically detected automatically (EDID)
• Works as plug & play in most cases
• USB touch may require driver support, but is often straightforward

USB-C display

• Requires DisplayPort Alt Mode support on the USB-C port
• Needs proper configuration of:
  • USB controller
  • display pipeline
  • sometimes device tree or kernel drivers
• Not always detected automatically

As a result:

• USB-C displays are not guaranteed plug & play on advanced embedded MPU systems
• USB-C displays are plug & play on popular Linux distributions and Windows
• Integration effort depends on platform support

Key takeaway

The presence of a USB-C connector does not define display capability.

• A display with USB-C typically uses it for touch or auxiliary functions
• A USB-C display uses it as a full video interface with integrated power and data

From a system architecture perspective, this difference affects:

• signal routing
• number of interfaces
• software complexity

Understanding this distinction is essential when integrating displays into embedded platforms.