
515
Table 515. MPEG2 DVB Transmit Bandwidth Classes
CLASS MXC
VALUES
MAX TSP B/W
(Mbps)
MAX SP B/W
(Mbps)
MAX 1394 BW
(Mbps)
POSSIBLE MPEG2 – DVB 1394
PACKET SIZE, BYTES (Decimal)
0
1.504
1.536
2.816
20, 44
1
3.008
3.072
4.352
20, 68
2
6.016
6.144
7.424
20, 116
3
12.032
12.288
13.568
20, 212
4
24.064
24.576
25.856
20, 212, 404
5
36.096
36.864
38.144
20, 212, 404, 596
6
48.128
49.152
50.432
20, 212, 404, 596, 788
7
60.160
61.440
62.270
20, 212, 404, 596, 788, 980
TSP BW:
Transport stream package bandwidth, based on 188-byte MPEG2 cell
SP BW:
Source packet bandwidth. Based on 192-byte MPEG2 cell
1394 BW:
Overall BW on 1394 bus. Based on 212-byte MPEG2 packet.
5.5.1.2
MPEG2 Receive
ceLynx can be formatted to strip any of the 1394 isochronous or CIP headers from received packets before
data is stored in the data buffer. The ceLynx can be programmed to strip the time stamp off the packet before
storing in the data buffer, or to keep the time stamp with the data. The time stamp is stripped when
DB(N)CFG0.TSSTRIP is set to 1. This control bit can only be used if the ISO and CIP headers are also
removed. The time stamps can also be used to determine when the data is released to the application by
using the TSAGE and TSRelease bits. (See
Internal Functions
, Section 4, for more detail.)
Table 516. MPEG2 Receive Header Stripping
MPEG2 RECEIVE
PACKET HEADERS
REGISTERS SETTINGS USED TO
STRIP HEADERS
ISO HEADER
RXDPB(N)CFG0.STRIPHDR0
CIP0
RXDPB(N)CFG0.STRIPHDR1
CIP1
RXDPB(N)CFG0.STRIPHDR2
TIME STAMP
DB(N)CFG0.TSSTRIP
NOTE:
The RXDPB(N)CFG3 and RXDPB(N)CFG4 registers allow ceLynx to filter
incoming packets. ceLynx can receive packets based on source ID, data length,
or header 0 information. The MASK bits allow the filter to mask off bits of the
incoming packet.
The packet control token should not be included with received MPEG2 data.
Either the host or HSDI can access the data buffer. The host can access the data
buffer through register DB(N)ACC0 for the associated buffer.
5.5.2
DirecTV Data
ceLynx supports both 130 byte and 140 byte DirecTV data. For DirecTV 140-byte data, ceLynx expects the
application to add the 10-byte header before sending the data to ceLynx for transmit. For DirecTV 130-byte
data, ceLynx automatically adds the 10-byte header to the 130-byte packet before transmitting over 1394.
The 10-byte header can be programmed using internal ceLynx CFRs.