Portable Retina Display Driven by USB Type-C

Get Clearly Know about USB Type-C Connector

Get Clearly Know what we should do

Implementing DisplayPort without an analog switch/multiplexer
The first products supporting DisplayPort Alternate Mode on a USB Type-C connector did so using external multiplexers. A better way to achieve the same thing is to implement a single USB/DisplayPort port that connects directly to a Type-C connector.

The Synopsys DesignWare USB-C 3.1/DisplayPort solution has a USB/DisplayPort comboPHY with a built-in digital multiplexer or crossbar switch that supports USB 3.1 Gen2 at 10Gbit/s and the HBR3 (HighBitRate3) variant of DisplayPort at 8.1Gbit/s. The digital crossbar switch (Figure 2) ensures the integrity of these high-bitrate signals.

Supporting high-resolution displays and Display Stream compression
Full HD TVs are common now, 4K TVs and monitors are widely used, and some panel makers are already exploring 8K (7680x4320pixel) display options. Driving such panels will be a challenge.

The DesignWare USB-C 3.1/DisplayPort solution supports DisplayPort 1.3 and 1.4. The DisplayPort 1.3 implementation has four lanes of HBR3, to support 4K displays with RGB color representations and 60Hz or 90Hz frame rates, or 8K displays with YUV color representations and 30Hz frame rates.

To run displays with higher specifications demands the use of the visually lossless Display Stream Compression (DSC) standard. This is the main enhancement of DisplayPort 1.4 over 1.3, and is directly supported in the DesignWare USB-C 3.1/DisplayPort solution. Implementation takes a fairly high gate count and so DSC is not yet widely used, but it will probably be needed in high-resolution/high refresh-rate virtual- and augmented-reality applications.

Protecting premium content with HDCP 1.4 and 2.2
Media organizations want to protect their content at every step of the distribution chain, which is why HDCP was developed to protect the link between source and display.

The DesignWare DisplayPort TX controller offers the HDCP 1.4 support necessary to protect HD and Full HD resolutions. Protecting 4K UHD and 8K video streams demands HDCP 2.2 support, which for security reasons is implemented in an Embedded Security Module outside the DisplayPort TX controller (see Figure 1).

Supporting multiple displays
The DesignWare USB-C 3.1/DisplayPort solution also supports DisplayPort Multi Stream Transport (MST), which enables one source to drive several monitors from one connector. Monitors with MST support are daisy-chained. Monitors without MST support connect as the last monitor in the MST daisy-chain, or to a DisplayPort hub. The Synopsys solution supports up to four streams. The total available bandwidth is shared between the monitors, so that, for example, four FHD monitors can be supported using four lanes of HBR2 without requiring the use of DSC.
Simultaneous USB and DisplayPort
Figure 2 shows the USB, DisplayPort and simultaneous USB and DisplayPort modes supported on the Type-C connector. Not all current DisplayPort Alt Mode implementations allow simultaneous USB and DisplayPort. Also, many current Type-C implementations are limited to USB 3.0 5G and the HBR2 variant of DisplayPort 1.2 at 5.4Gbit/s. Even if USB 2.0 is still available in DisplayPort (only) mode, this is limiting for some Type-C use cases. Synopsys’ DesignWare USB-C 3.1/DisplayPort Solution fully supports simultaneous 10 Gbit/s USB 3.1 and two lanes of DisplayPort 1.4 HBR3 at 8.1Gbit/s per lane, enabling 4K UHD monitor support with simultaneous 10Gbit/s file transfers and high-bandwidth networking.