| 摘要 |
<p>As shown in Figure 2, a teletext decoder has a multi-page memory (MEM) comprising a plurality of memory portions (CH0 to CH3) in which individual pages can be stored on a priority basis. The numbers of selected pages are entered into page request registers (PR0 to PR3) and when the number of a selected page is detected by the relevant one of page comparators (PC0 to PC3) a found bit (FB) is produced by the relevant one of flip-flops (FB0 to FB3) and recorded in the memory portion allotted to the selected page by processor means (PM). In order to ensure that the end of a selected page can also be detected, one of the memory portions is allotted to store every page received so that a found bit is always produced at the end of a selected page stored in another memory portion. The processor means (PM) uses this latter found bit to signify detection of the end of the selected page.</p> |
