IC Component Interfaces

Many solutions for transferring digital video between chips are derived from the pro-video interconnect standards. Chips for the pro-video market typically support 10 or 12 bits of data per video component, while chips for the consumer market typically use 8 bits of data per video component. BT.601 and BT.656 are the most popular interfaces.

YCbCr Values: 8-bit Data

Y has a nominal range of 0×10–0xEB. Values less than 10H or greater than 0xEBH may be present due to processing. Cb and Cr have a nominal range of 0×10–0xF0. Values less than 0×10 or greater than 0xF0 may be present due to processing. YCbCr data may not use the values of 00H and FFH since those values may be used for timing information.

During blanking, Y data should have a value of 0×10 and CbCr data should have a value of 0×80, unless other information is present.

YCbCr Values: 10-bit Data

For higher accuracy, pro-video solutions typically use 10-bit YCbCr data. Y has a nominal range of 0×040–0×3AC. Values less than 0×040 or greater than 0×3AC may be present due to processing. Cb and Cr have a nominal range of 040H–3C0H. Values less than 0×040 or greater than 0×3C0 may be present due to processing. The values 0×000–0×003 and 0×3FC–0×3FF may not be used to avoid timing contention with 8-bit systems.

During blanking, Y data should have a value of 0×040 and CbCr data should have a value of 0×200, unless other information is present.

RGB Values: 8-bit Data

Consumer solutions typically use 8-bit R′G′B′ data, with a range of 0×10–0xEB (note that PCs typically use a range of 0×00–0xFF). Values less than 0×10 or greater than 0xEB may be present due to processing.

During blanking, R′G′B′ data should have a value of 0×10, unless other information is present.

RGB Values: 10-bit Data

For higher accuracy, pro-video solutions typically use 10-bit R′G′B′ data, with a nominal range of 0×040–0×3AC. Values less than 0×040 or greater than 0×3ACH may be present due to processing. The values 0×000–0×003 and 0×3FC–0×3FF may not be used to avoid timing contention with 8-bit systems.

During blanking, R′G′B′ data should have a value of 0×040, unless other data is present.

BT.601 Video Interface

The BT.601 video interface has been used for years, with the control signal names and timing reflecting the video standard. Supported active resolutions and sample clock rates are dependent on the video standard and aspect ratio.

Devices usually support multiple data formats to simplify using them in a wide variety of applications.