Datasheet

2−44
2.20.54 Teletext Filter Control Register
Address BBh
Default 00h
7 6 5 4 3 2 1 0
Reserved Filter logic Mode TTX filter 2 enable TTX filter 1 enable
Filter logic: allows different logic to be applied when combining the decision of filter 1 and filter 2 as follows:
00 = NOR (Default)
01 = NAND
10 = OR
11 = AND
Mode:
0 = Teletext WST PAL mode B (2 header bytes) (default)
1 = Teletext NABTS NTSC mode C (5 header bytes)
TTX filter 2 enable:
0 = Disabled (default)
1 = Enabled
TTX filter 1 enable:
0 = Disabled (default)
1 = Enabled
If the filter matches or if the filter mask is all 0s, then a true result is returned.