Altera SDI II MegaCore User Manual
Page 58
Video Format
Field
Line Number
625i
1
9
2
322
1080i
1
10
2
572
525p
—
13
625p
—
9
720p
—
10
1080p
—
10
For dual link HD-SDI interface, the payload ID packets are placed only in the Y data stream of both links.
This submodule in the transmitter data path modifies the Y data stream that passes through.
Note: This submodule introduces a latency of a few clock cycles. The C data stream is delayed by a few
clock cycles to keep it synchronized with the Y data stream.
The following rules apply for inserting and overwriting payload ID packets:
• Rule 1: If there is no ancillary packet at the beginning of the HANC space on a line where the payload
ID packet is supposed to occur, the submodule inserts the payload ID packet at the beginning of the
HANC space.
• Rule 2: If there is an existing payload ID packet at the beginning of the HANC space on a line where
the payload ID packet is supposed to occur, the submodule overwrites the packet with the new payload
ID information if the
tx_vpid_overwrite
signal is high. If the
tx_vpid_overwrite
signal is low, no
overwrite takes place.
• Rule 3: If there is a different type of ancillary packet or multiple ancillary packets at the beginning of
the HANC space on a line where the payload ID packet is supposed to occur, the submodule does not
overwrite the existing ancillary packet(s). Instead, it looks for empty space in the HANC space to insert
the payload ID packet after the existing ancillary packet(s). If it finds a payload ID packet later in the
HANC space before if finds an empty space, it overwrites the existing payload ID packet with the new
data if the
tx_vpid_overwrite
signal is high. If the
tx_vpid_overwrite
signal is low, no overwrite
takes place.
For correct payload ID insertion, assert the
tx_trs
signal for the first word of both EAV and SAV TRS as
shown in the
timing diagram.
4-16
Insert Payload ID
UG-01125
2015.05.04
Altera Corporation
SDI II IP Core Functional Description