HMP8170CN Intersil Corporation, HMP8170CN Datasheet - Page 11

• Manufacturer Part Number: HMP8170CN
• Description: NTSC/PAL Video Encoder
• Manufacturer: Intersil Corporation

NOTES:
The even parity (EP and EP#) bits are ignored.
Line = Data Register Select: 0 = Line 20; 1 = 283.
The WSS CRC data bits are ignored during PAL operation but must be included in the transfer.
X = Don’t Care.
NOTE: The CRC registers are always ignored during PAL operation.
Teletext
The HMP817x supports ITU-R BT.653 625-line and 525-line
teletext system B and C generation. WST (World System
Teletext) is the same as BT.653 system B. NABTS (North
American Broadcast Teletext Specification) is the same as
BT.653 525-line system C. NABTS is also used to transmit
Intel Intercast information.
During the teletext encoding, the line’s pixel inputs are
ignored. The teletext information includes a 16-bit clock
synchronization code; the HMP817x automatically
generates it.
ENABLE BITS
Data Block Number
WSS Data Nibble 3
WSS Data Nibble 2
WSS Data Nibble 1
WSS Data Nibble 0
WSS CRC Nibble 1
WSS CRC Nibble 0
Data Word Count
WSS
PIXEL INPUT
00
01
10
11
Preamble 1
Preamble 2
Preamble 3
Reserved
Reserved
Data ID
CRC
None
20 (NTSC)
17 (M PAL)
23 (Other PAL)
283 (NTSC)
280 (M PAL)
336 (Other PAL)
20, 283 (NTSC)
17, 280 (M PAL)
23, 336 (Other PAL)
TABLE 8. BT.656 ANCILLARY DATA FORMAT FOR WIDESCREEN SIGNALLING DATA
OUTPUT LINE(S)
11
P14#
P15
ep#
ep#
ep#
ep#
ep#
ep#
ep#
ep#
ep#
ep#
ep#
HMP8170, HMP8171, HMP8172, HMP8173
0
1
1
TABLE 9. WIDESCREEN SIGNALLING MODES
P14
ep
ep
ep
ep
ep
ep
ep
ep
ep
ep
ep
0
1
1
X
283A, 283B,
WSS Data
WSS Data
CRC283
Ignored
Ignored
P13
0
1
1
1
0
0
0
0
0
0
0
0
0
0
X
WSS REGISTERS
The teletext output level depends on the video format. For
system B teletext, the output level is 66 IRE for a logic 1 and 0
IRE for a logic 0. All transitions between levels are controlled to
have a raised-cosine shape with a rise or fall time of 200ns. For
system C teletext, the output level is 70 IRE for a logic 1 and 0
IRE for a logic 0. All transitions between levels are controlled to
have a raised-cosine shape with a rise or fall time of 200ns.
The HMP817x generates teletext output on any scan line
that includes teletext data in that line’s BT.656 ancillary data.
The encoder must receive the ancillary data before the SAV
sequence in order to output the teletext data. Table 10 shows
the BT.656 ancillary data format for loading the teletext data
registers.
P12
X
0
1
1
1
0
0
0
0
0
0
0
0
0
0
WSS Data
WSS Data
20A, 20B,
Ignored
Ignored
CRC20
bit 11
bit 7
bit 3
bit 3
P11
X
0
1
1
0
0
0
0
0
0
0
0 = Loaded
0 = Loaded
1 = Output
1 = Output
bit 10
Always 1
Always 1
bit 6
bit 2
bit 2
P10
X
0
1
1
0
0
0
0
0
0
0
283
WRITE STATUS BIT
bit 13
bit 9
bit 5
bit 1
bit 5
bit 1
P9
X
0
1
1
1
0
1
0
0
0 = Loaded
0 = Loaded
1 = Output
1 = Output
Always 1
Always 1
20
bit 12
Line
bit 8
bit 4
bit 0
bit 4
bit 0
P8
X
0
1
1
1
0
0
0