Datasheet

TVP5147M1

www.ti.com

SLES140G –JULY 2005–REVISED FEBRUARY 2012

Table 2-87. VDP TTX Filter and Mask Register

Subaddress B1h B2h B3h B4h B5h B6h B7h B8h B9h BAh

Default 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h

Subaddress 7 6 5 4 3 2 1 0

B1h Filter 1 Mask 1 Filter 1 Pattern 1

B2h Filter 1 Mask 2 Filter 1 Pattern 2

B3h Filter 1 Mask 3 Filter 1 Pattern 3

B4h Filter 1 Mask 4 Filter 1 Pattern 4

B5h Filter 1 Mask 5 Filter 1 Pattern 5

B6h Filter 2 Mask 1 Filter 2 Pattern 1

B7h Filter 2 Mask 2 Filter 2 Pattern 2

B8h Filter 2 Mask 3 Filter 2 Pattern 3

B9h Filter 2 Mask 4 Filter 2 Pattern 4

BAh Filter 2 Mask 5 Filter 2 Pattern 5

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 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

D[3] H[3] D[2] H[2] D[1] H[1] D[0] H[0]

Only the 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 hamming protection bits.

For a 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 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

R[0] H[3] M[2] H[2] M[1] H[1] M[0] H[0]

R[4] H[7] R[3] H[6] R[2] H[5] R[1] 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).

Submit Documentation Feedback

Product Folder Link(s): TVP5147M1