Z86228

The Z86228 (Line 21 Closed-Caption Controller) is a single I.C. designed to provide the functional performance of a  21C Decoder module. This Superintegration™ VLSI device is completely self contained requiring only composite video, a horizontal timing signal as input and an external keyer (i.e., video switch between TV video and Closed- Caption video) to produce captioned video. The Z86228 uses a wired logic approach to perform the functions selected through its input control signals. It is fabricated using standard CMOS technology and designed to achieve the lowest possible cost.

The Z86228 is intended for use in a set-top decoder or in any television receiver conforming to the NTSC standard. It is capable of processing and displaying all standard L21C format transmissions including the codes specified by the FCC "Report and Order" on GEN Docket No. 91-1, dated April 12, 1991. In addition, the device conforms to  he Electronic Industry Association's Recomended Practice 608, which provides supplemental guidelines for the transmission of captions, text, and Extended Data Service s (EDS) on NTSC Field 2. Extended Data Services (EDS) packets encoded on Field 2 , may be displayed in either of two screen formats. If and when PAL and SECAM TV standards define a protocol using the Line 21 format, this design will be readily convertible to that standard.