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Texas Instruments TMS320C64x DSP manual BT.656 Video Capture Mode, 1 BT.656 Capture Channels

Models: TMS320C64x DSP

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BT.656 Video Capture Mode

3.2 BT.656 Video Capture Mode

The BT.656 capture mode captures 8-bit or 10-bit 4:2:2 luma and chroma data multiplexed into a single data stream. Video data is conveyed in the order Cb,Y,Cr,Y,Cb,Y,Cr, etc. where the sequence Cb,Y,Cr refers to co-sited luma and chroma samples and the following Y value corresponds to the next lu- minance sample. The data stream is demultiplexed and each component is written in packed form into separate FIFOs for transfer into Y, Cb, and Cr buff- ers in DSP memory. (This is commonly called planar format.) The packing and order of the samples is determined by the sample size (8-bit or 10-bit) and the selected endianess of the DSP.

The ITU-BT.656 standard provides for either 8-bit or 10-bit component sam- ples. When 10-bit samples are used, the 2 least significant bits are considered fractional values. Thus for 8-bit operation, input data is aligned to the most sig- nificant bits (9–2) of the input and the two least-significant bits are ignored.

In BT.656 video capture mode, data bytes in which the 8 most significant bits are all set to 1 (FF.0h, FF.4h, FF.8h, FF.Ch) or are all set to 0 (00.0h, 00.4h, 00.8h, 00.Ch) are reserved for data identification purposes and consequently, only 254 of the possible 256 8-bit words (or 1016 of 1024 10-bit words) may be used to express signal value.

3.2.1BT.656 Capture Channels

In dual channel operation, the video port can support capture of two BT.656 data streams or one BT.656 data stream and one raw data stream. In the latter case, the BT.656 stream may occur on either Channel A or Channel B. In either case, the BT.656 stream(s) must have embedded timing reference codes and the appropriate VCTL input must be used as a CAPEN signal.

If the port is configured for single channel operation, capture will take place on Channel A only. The unused half of the VDATA bus may be used for GPIO or for another peripheral function. For single channel operation, non-standard BT.656 data streams without embedded timing reference codes are supported through the use of the timing control (VCTL) input signals.

SPRU629

Video Capture Port

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Texas Instruments TMS320C64x DSP manual BT.656 Video Capture Mode, 1 BT.656 Capture Channels
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TMS320C64x DSP specifications

The TMS320C64x DSP family from Texas Instruments represents a significant milestone in the realm of digital signal processing. Launched as part of the C6000 series, the C64x DSPs are designed for high-performance applications requiring intensive computational capabilities, such as telecommunications, audio processing, video processing, and industrial control systems.

One of the standout features of the TMS320C64x DSP is its VLIW (Very Long Instruction Word) architecture, which allows for an exceptionally high level of parallelism. This architecture enables multiple instructions to be executed simultaneously, boosting the overall throughput and allowing for complex data processing tasks to be completed more quickly than with conventional DSPs.

The C64x DSPs also boast an impressive clock frequency range, typically up to 1 GHz, delivering substantial computational power for real-time processing goals. Additionally, these processors feature extensive on-chip memory, including L1 and L2 cache, which significantly enhances data access speeds and helps reduce bottlenecks during high-demand processing tasks.

Another key characteristic of the TMS320C64x family is its support for advanced instruction sets optimized for specific applications. These include SIMD (Single Instruction, Multiple Data) capabilities, allowing for efficient handling of large datasets often involved in multimedia processing or complex signal manipulation.

For connectivity, these DSPs often integrate advanced interfaces such as EMIF (External Memory Interface) and McBSP (Multichannel Buffered Serial Port), facilitating seamless interaction with a variety of peripheral devices. This ensures that the DSP can suit different application needs and integrate well into various system architectures.

Texas Instruments emphasizes low power consumption with the C64x DSPs, making them ideal for portable or energy-sensitive applications. Advanced power management techniques and technologies, such as dynamic voltage and frequency scaling, are incorporated to further enhance energy efficiency without compromising performance.

In summary, the Texas Instruments TMS320C64x DSP family stands out due to its high-performance capabilities driven by a VLIW architecture, high clock speeds, extensive memory options, a rich instruction set, and advanced connectivity features, all while maintaining power efficiency. These characteristics make it an exceptional choice for developers looking to integrate robust digital signal processing into their applications, whether in telecommunications, audio and video processing, or embedded control systems.