[ZORAN Corporation]

ZR36505 - VBI (Teletext) pipe and Remote Control interface for USB TV applications

The ZR36505 is a complimentary chip for the ZR36504 in USB TV applications. Combined with certain video decoders, it adds a VBI (Vertical Blank Interval) data pipe to the system, which utilizes the general purpose Bulk channel of the NT1004. The VBI is used by TV broadcast providers to send digital data hidden in the analog video signal. One or more video lines, taken from lines 1-21 of each video field are used for carrying this information - each line providing about 9,600 bits/sec data rate.
The ZR36505 provides the application S/W with access to data such as Teletext, Close-Caption, Intercast, IR receiver samples, etc. It uses a 1KByte SRAM buffer to grabe the processed data from the video decoder during the Blank Interval time slot, and sends this data to the USB through the ZR36504 Bulk pipe during the time left prior to beginning of next Blak Interval. For the remote Control interface, the input pin IO_1 is sampled at 4Ksamp/sec rate, and the sampled bits are moved to host computer via the (NT1004) for S/W process.

Features
• Enables Teletext and Close-Caption
• Supports WST625, WST525, CC625, CC525, US NABTS, MOJI (Japanese), and JFS formats
• Provides Remote Control interface with IR receiver (sampled at 4K samp./sec.)
• Low Cost, Low Power, 3.3v operated
• 24-pin SOIC package