W9968CF

The W9968CF is a digital video processing chip offered by Winbond to facilitate adapterless connection between digital video camera and personal computer for video and still image capturing and editing, video e-mail, and video conferencing applications. Low-cost, high-performance, and high-quality digital video camera can be realized by using Winbond¢s W9968CF, which includes Universal Serial Bus (USB) technology and the international standard JPEG compression.

The digital video camera is becoming the next great input device for the PC. USB is now a common PC standard for connecting peripheral products, which features low cost, hot-attachable plug and play, adequate 12 Mb/s full speed bandwidth, and simultaneous attachment of multiple devices. The W9968CF has built-in full speed USB controller which benefits from using the isochronous data transfer mode of the USB bus, and which is compliant with the full power management requirements of the USB specification, including startup, operating, and suspend modes. To prevent saturation of the USB bus, the W9968CF uses no more than 8 Mb/s of available bandwidth to ensure the continued operation of other low bandwidth devices such as USB mice and keyboards.

Although USB provides a low-cost solution for low to medium speed peripherals, its 12 Mb/s bandwidth is not enough for high-quality and high-performance digital video camera. High-quality and low-cost compression is necessary to boost frame rate for a high-performance digital video camera. The W9968CF has built-in the baseline JPEG compression, which corresponds to the ISO/IEC international standard 10918-1, with YCbCr4:2:2 or YCbCr4:2:0 components in non-interleaved scan. The baseline JPEG implementation in the W9968CF includes Discrete Cosine Transform (DCT), quantization, zigzag scan, and Huffman encoder. With JPEG compression, the W9968CF can easily achieve good quality 30 frames per second (fps) in CIF resolution (352´288) and 10~15 fps in VGA resolution (640´480) by consuming no more than 8 Mb/s USB bandwidth.

The W9968CF can accept NTSC, PAL, or VGA video in 8- or 16-bit YCbCr4:2:2 format, square or rectangular pixels, and converts to sub-QCIF (128´96), QCIF (176´144), CIF (128´96), SIF (352´240), 320´240, or VGA (640´480) format. Built-in cropping window control and arbitrary scaling in both the horizontal and vertical directions can serve as the digital pan and zoom over a user-specified region for camera control.

In addition to USB interface, the W9968CF also supports an 8-bit microcontroller interface for portable PC camera applications. Up to 24 still images in 640´480 VGA format can be captured, JPEG compressed, and stored into an external 2 Mbytes Flash memory when in the portable mode. An on-chip DRAM controller is used to interface to SDRAM or EDO DRAM through a 16-bit data bus.

An external serial E2PROM is also supported if IHV-specific Vendor ID and Product ID are needed. The IHV-specific information can be also provided by an external microcontroller if present to save the cost of an E2PROM. The W9968CF is a 3.3 V device with TTL-compatible 3.3 V or 5.0 V I/O, and is packaged in a 128L QFP.