Power Modes
The receiver also controls the activity state transitions as a result of the power, buttons and input data (see Figure 6). The possible states include:
- Low power mode - The monitor power is on, but there is no signal from the source (orange LED).
- Self-test mode - The monitor power is on, and the DisplayPort cable is disconnected.
- Normal mode - The monitor power is on, and there is an active DisplayPort signal (green LED).
- Error mode - The monitor power is on, but there is an abnormal condition such as an out-of-range graphics mode (flashing orange LED).
- Failsafe mode - the monitor power is on and in safe timing mode, which is the default mode of 640×480 @60Hz. The receiver will use this setting after it is powered up but before it is completely configured.
Figure 6. DisplayPort Power Modes
Conclusion
DisplayPort combines audio and video in a single interface and cable, providing higher-performance output at a fraction of the cost of other interfaces. DisplayPort can save greater than half the pin count and wires, and provide 25 percent or more of the bandwidth than VGA or DVI - ultimately improving the performance and bandwidth of video display. With the amount of bandwidth that DisplayPort can pump out, it is far more efficient per data transfer rate than any of the other display interfaces.
The cost, performance, versatility and small size are all reasons that DisplayPort is quickly becoming the dominant display interface standard for PCs and handheld devices.
About the Author
Jeff Lukanc is the Director of Program Management in the Video Display Operations group at Integrated Device Technology (IDT). He has a BSEE from the University of Illinois, an MSEE from SMU and an MBA from St. Thomas University. He can be reached at Jeff.Lukanc@idt.com
