67 vdp ttx filter control register – Texas Instruments TVP5147M1PFP User Manual
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Functional Description
62
SLES140A—March 2007
TVP5147M1PFP
2.11.67 VDP TTX Filter Control Register
Subaddress
BBh
Default
00h
7
6
5
4
3
2
1
0
Reserved
Filter logic [1:0]
Mode
TTX filter 2 enable
TTX filter 1 enable
Filter logic [1:0]: Allow 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: indicates which teletext mode is in use.
0 = Teletext filter applies to 2 header bytes (default)
1 = Teletext filter applies to 5 header bytes
TTX filter 2 enable: provides for enabling the teletext filter function within the VDP.
0 = Disabled (default)
1 = Enabled
TTX filter 1 enable: provides for enabling the teletext filter function within the VDP.
0 = Disabled (default)
1 = Enabled
If the filter matches or if the filter mask is all 0s, then a true result is returned.