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What is Billboard device?
Billboard is a new USB device class introduced by USB-IF to provide a mechanism to report the Alternate Mode(s) supported by Device Container if the Alternate Mode negotiation fails. More details on Billboard Devices are available in the USB Billboard Device Class specification at the following link.
What is USB alt mode?
Alt Mode is a functional extension of USB-C which enables the USB connection to carry non-USB signals. Alt Mode(s) are optional capabilities that are unique to the USB-C connector or port that allow technologies, like DisplayPort and Thunderbolt 3, to be transmitted.
What is a USB 2.0 billboard?
USB 2.0 Billboard Device Class is defined to communicate the details of supported Alternate Modes to the computer host OS. It provides user readable strings with product description and user support information. Billboard messages can be used to identify incompatible connections made by users.
What is a billboard device in Windows 10?
Billboard Device Class. When a device which supports Alternate Mode is connected to a non-supporting host device, a pop-up window, or the Billboard, will show information of the device status. Billboard notifies users the status of use when the device does not support Alternate Mode.
Can USB 3.1 Type A carry video?
USB 3.1 (aka USB 3.1/gen 1 and USB 3.1/gen 2) is the successor to USB 3.0. Identifiable by its bright turquoise port, USB 3.1/gen 2 doubles the transfer speed of 3.0 to a whopping 10 Gbps. With 4 data lanes, USB 3.1 Type-C can even carry DisplayPort and HDMI video signals, further adding to its ubiquity.
Can a USB Billboard be exposed in alternate mode?
The device may expose the USB Billboard Device Classinterface again with updated capabilities. According to this, exposure of the interface after Alternate Mode has been entered is optional, and may be re-exposed later with updated information if need be.
How does a USB Billboard work in Type C?
On the other hand, if a monitor that supports Type-C interface connects via Type-C but is not recognized as Alternate Mode, the OS will recognize the device as USB Billboard device, as shown in Figure 1. A Billboard message will pop up in the lower-right corner of the desktop to alert users of the current device status, as shown in Figure 2.
Do you need a billboard for USB 2.0?
As such it requires a USB 2.0 billboard device to be present to negotiate with the host and enter alt mode.
What happens if I expose my USB Billboard?
If the device enters the mode, it shall respond with an ACK and discontinue exposing the USB Billboard Device Classinterface. The device may expose the USB Billboard Device Classinterface again with updated capabilities.