TVP5147PFP Datasheet, PDF (69/98 Pages) Texas Instruments – NTSC/PPAL SECAM 2 X 10 BIT DIGITAL VIDEO DECODER WITH MACROVISION DETECTION INPUT AND 5 LINE COMB FILTER

Functional Description
For an NABTS system, the packet prefix consists of five bytes. Each byte contains 4 data bits (D[3:0])
interlaced with 4 Hamming protection bits (H[3:0]):
Bit 7
D[3]
Bit 6
H[3]
Bit 5
D[2]
Bit 4
H[2]
Bit 3
D[1]
Bit 2
H[1]
Bit 1
D[0]
Bit 0
H[0]
Only data portion D[3:0] from each byte is applied to a teletext filter function with corresponding pattern bits
P[3:0] and mask bits M[3:0]. The filter ignores the Hamming protection bits.
For WST system (PAL or NTSC), the packet prefix consists of two bytes. The two bytes contain three bits of
magazine number (M[2:0]) and five bits of row address (R[4:0]), interlaced with eight Hamming protection bits
H[7:0]:
Bit 7
R[0]
R[4]
Bit 6
H[3]
H[7]
Bit 5
M[2]
R[3]
Bit 4
H[2]
H[6]
Bit 3
M[1]
R[2]
Bit 2
H[1]
H[5]
Bit 1
M[0]
R[1]
Bit 0
H[0]
H[4]
The mask bits enable filtering using the corresponding bit in the pattern register. For example, a 1 in the LSB
of mask 1 means that the filter module must compare the LSB of nibble 1 in the pattern register to the first data
bit on the transaction. If these match, then a true result is returned. A 0 in a bit of mask means that the filter
module must ignore that data bit of the transaction. If all 0s are programmed in the mask bits, then the filter
matches all patterns returning a true result (default 00h).
2.11.62 VDP TTX Filter Control Register
Subaddress BBh
Default
00h
7
6
5
Reserved
4
3
Filter logic [1:0]
2
Mode
1
TTX filter 2 enable
0
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.
SLES099A—April 2004
TVP5147PFP
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