All video systems require management of video timing signals, which are used to synchronize processes. The Video Timing Controller serves the function of both detecting and generating these timing signals.
The input side of this core automatically detects horizontal and vertical synchronization pulses, polarity, blanking timing and active video pixels. While on the output, it generates the horizontal and vertical blanking and synchronization pulses used with a standard video system including support for programmable pulse polarity. The core is commonly used with the Video in to AXI4-Stream core to detect the format and timing of incoming video data or with the AXI4-Stream to Video out core to generate outgoing video timing for downstream sinks such as a video monitor.
This Figure shows a typical video frame including timing signals.
IMPORTANT: All signals are shown with active-High polarity.
A video frame can be completely described in terms of timing by only a few definitions. A video frame comprises active video and blanking periods. The vertical and horizontal synchronization signals describe the video frame timing, which includes active and blanking data. In addition, the frame synchronization signals can be used to synchronize video data from one component to another within a video system. There are additional signals that can also be used to control the video system, such as a signal to differentiate valid chroma samples.
Video systems may utilize different combinations of blank, synchronization or active signals with various polarities to synchronize processing and control video data. The Video Timing Controller simplifies working with video timing signals by providing a highly programmable and flexible core that allows detection and generation of the various timing signals within a video system.