GENNUM CORPORATION
522 - 45 - 05
17
G
Fig. 9: Arbitrary Data Packet Input Timing Diagram
The arbitrary data packet words are defined as follows:
ADF: Ancillary Data Flag.
The ancillary data flag marks the
beginning of an ancillary packet and is automatically
generated by the GS9023.
DID: Data ID.
Configured in
“
PKTID[7:0]
”
of Host Interface
Register #5h. The two most significant bits are internally
generated by the GS9023.
SDID: Secondary Data ID.
The Secondary Data ID is
handled as user input data.
DC: Data Count.
The data count represents the number of
user data words to follow, up to a maximum of 255 words.
The data count is handled as user input data. For the
GS9023 the maximum data count is 253 since the total
number of words that can be input is 255 less the SDID and
DC words.
UDW: User Data Word.
CS: Checksum.
The checksum consists of nine bits. The
checksum is used to determine the validity of the words
data ID through user data. It is the sum of the nine least
significant bits of the words data ID through user data. The
checksum is automatically generated by the GS9023.
Error Detection
The GS9023 provides error status information in Host
Interface Register #7h as described in Table 14. All errors
are cleared when Host Interface Register #7h is read.
TABLE 11: Multiplex Position For Arbitrary Data Packet
VIDEO STANDARD
RECOMMENDED
MULTIPLEX LINE
HORIZONTAL STARTING
POSITION (WORD #)
HORIZONTAL ENDING
POSITION (WORD #)
525/D2
9/272
340
360
525/D1
14/277
0
1439
525/16:9
14/277
0
1919
NOTE: 525/4:4:4:4 and all 625 line video standards are not supported.
* Horizontal Starting Position 0 is the first word of the active picture.
PCLK (I)
PKTEN (I)
1 clk
1 clk
Valid data
PKT[8:0] (I)
1 - The ancillary data flag, ADF, is one word in composite systems (ANSI/SMPTE 259M)
and three words in component systems (ANSI/SMPTE 125M).
2 - The ADF, DID and CHKSUM words are automatically generated by the GS9023.
A
1
S
D
D
2
U
U
U
U
U
U
U
C
A
1
A
1
NOTE: