Texas Instruments TVP5147M1PFP manual VDP TTX Filter And Mask Registers

Models: TVP5147M1PFP

1 100
Download 100 pages 24.7 Kb
Page 69
Image 69
2.11.66 VDP TTX Filter And Mask Registers

Functional Description

2.11.66 VDP TTX Filter And Mask Registers

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 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

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).

SLES140A—March 2007

TVP5147M1PFP

61

Page 69
Image 69
Texas Instruments TVP5147M1PFP manual VDP TTX Filter And Mask Registers