STM7710

Architecture

11/23

A five input, two output transport stream merger/router allows any of the three external

inputs to be routed to the PTI. A fourth input is provided for routing internal transport

streams stored in memory to the PTI. A fifth input receives a full/partial transport stream

created by the PTI and can output it from the STM7710 through the bidirectional interface

when configured as an output. This allows transport streams to be sent to a D-VCR through

an IEEE1394 link layer controller, EMI or USB 2.0 port. Routing can be concurrent to two

outputs.

When TS0 is operating in serial mode, an NRSS-A interface is available for routing serial

transport streams to and from an NRSS-A compatible CA module.

The stream merger/router is also capable of merging any three of the input streams into one

transport stream and forwarding this to the PTI allowing the PTI to process three

independently sourced transport streams at the same time.

2.5.2

Programmable transport interface (PTI)

The PTI performs PID filtering, demultiplexing, descrambling, and data filtering on up to

three transport streams at the same time up to an aggregate rate of 100 Mbit/s. The PTI

extracts PCRs with time stamps and makes them available to the CPU for clock recovery

and audio/video synchronization.

PES data is transferred by DMA to memory buffers. Section data is transferred by DMA to

separate buffers for further processing by the CPU. The PTI can also extract indexing

information and then transfer packets, using DMA, to an intermediate buffer for writing to

HDD.

Transport streams supported include DIRECTV®, DVB, ATSC, OpenCable, DCII and ARIB

BS4.

The PTI performs PID filtering to select audio, video and data packets to be processed. Up

to 48 PID slots are supported.

The PTI can descramble streams using the following ciphers:

●

DES-ECB including DVS-042 termination block handling,

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DES-CBC including DVS-042 termination block handling,

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DES-OFB,

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Multi2-ECB including DVS-042 termination block handling,

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Multi2-CBC including DVS-042 termination block handling,

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Multi2-OFB,

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DVB-CSA,

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Fast-I,

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NDS specific streams can also be supported by the integration of ICAM functionality.

The PTI has a 48 x 16-byte section filter core. Four filtering modes are available:

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Wide match mode: 48 x 16-byte filters,

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Long match mode: 96 x 8-byte filters,

●

Positive/negative mode: 48 x 8-byte filters with positive/negative filtering at the bit level.

Matching sections are transferred to memory buffers for processing by software.

When the PTI is required to output a transport stream, it can output the entire transport

stream or selected packets filtered by PID. A latency counter is provided to ensure packet

timing is preserved. Packets can also be substituted.