ELECTRONICS
S5N8947 (ADSL/Cable Modem MCU)
SAMSUNG ELECTRONICS
Page : 27
MagIC Team
6.5. SAR and Utopia Interface
The S5N8947 provides ATM layer Segmentation and Reassembly (SAR) function over a 8bit
UTOPIA interface. The S5N8947 delivers an integrated solution for performing the SAR tasks required to
communicate over an ATM network. The device translates packet-based data into 53-byte ATM cells that
are asynchronously mapped into various physical media. The S5N8947 can be effectively applied for
equipment requiring an interface between packet-based data and ATM-based networks.
6.5.1. Block Diagram
Reassembler
AAL5, 3/ 4, 0
Segmentor
AAL5, 3/4, 0
Scheduler
(CBR,UBR,rt-VBR,nrt-VBR)
Registers
Connection Memory
(Internal and/or External)
UTOPIA
and
FIFOs
System
I/F and
FIFOs
Figure 8 SAR function block diagram
6.5.2. Features and Benefits
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Supports CBR, UBR, rt-VBR and nrt-VBR traffic with rates set on a per-VC or per-VP basis.
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Supports AAL0 (raw cells) and AAL5 segmentation and reassembly.
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Segments and reassembles data up to about 70M bps via UTOPIA interface.
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Generates and verifies CRC-10 for OAM cells and AAL3/4 cells.
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Supports concurrent OAM cells and AAL5 cells on each active connection.
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Supports simultaneous segmentation and reassembly of up to 32 connections with internal memory
and up to 4K connections with external memory.
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On chip 8K bytes SRAM for internal connection memory.
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Supports Contents Addressable Memory (CAM) for channel mapping (up to 32 connections).
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Supports packet sizes up to 64K bytes.
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Supports scatter and gather packet capability for large packets
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Start of Packet offset available for ease of implementing bridging and routing between different
protocols.
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Provides glue-less UTOPIA level 2 interface (up to 7 PHYs).