CXD1948R Ver la hoja de datos (PDF) - Sony Semiconductor

Número de pieza

componentes Descripción

Lista de partido

CXD1948R

IEEE1394 Link Layer LSI for DVB and DSS

Sony Semiconductor 

CXD1948R

5-2. Transport Stream Data I/F

5-2-1. Data Bus

The data interface is 8 bit/16 bit, and switching is done by accessing the CFR AIDT16 register. (The default

value is 8 bit.)

5-2-2. Transport Packet Size

Data communication is done in transport stream packet units.

The data size for one packet can be set optionally by accessing the S_PacketSize register on the CFR.

S_PacketSize expresses the byte size of 1 source packet for isochronous communication.

For DVB specifications, this is 192 (data 188 bytes, source packet header 4 bytes).

5-2-3. Isochronous Additional Data

Optional data can be added to the transport stream packet when isochronous communication is performed.

Setting of the additional data is done by setting the CFR AddSize and AddData1 to AddData10 registers.

AddSize is a 4-bit register, and expresses the number of additional bytes for isochronous transmit/receive.

AddData1 to AddData10 are each 8-bit registers, and express the additional data for isochronous transmit/receive.

The default setting is no additional data.

The additional data is inserted between the source packet header and the transport stream data.

The smallest group of data that can be handed under IEEE1394 is 32 bits, so the setting must be such that the

total of the transport stream data and additional data is a 32-bit unit.

An example is shown below.

Example of Isochronous Communication Setting

When S_PacketSize = 192 and AddSize = 0 (example of setting for DVB)

Transport stream data

4 bytes

188 bytes

When S_PacketSize = 144 and TxAddSize = 10 (example of setting for DSS)

4 bytes

10 bytes

– 10 –

Transport stream data

130 bytes

Share Link: