TNETA1570 Datasheet, PDF (1/68 Pages) Texas Instruments – ATM SEGMENTATION AND REASSEMBLY DEVICE WITH INTEGRATED 64-BIT PCI-HOST INTERFACE

TNETA1570
ATM SEGMENTATION AND REASSEMBLY DEVICE
WITH INTEGRATED 64ĆBIT PCIĆHOST INTERFACE
SDNS033B − JUNE 1995 − REVISED MAY 1996
D Single-Chip Segmentation and Reassembly
Device (SAR) for Full-Duplex
ATM-Adaptation-Layer (AAL) Processing
D Integrated 64-Bit Peripheral-Component
Interface for Transferring Data and Control
Information for Packet Segmentation and
Packet Reassembly
D Provides Complete Encapsulation and
Termination of AAL5 Packets
D Supports Both Transmit and Receive Buffer
Chaining (Buffer Scatter/Gather)
D Provides for Early Segmentation of a
Transmit Packet by Beginning the
Segmentation Process Once a Transmit
Buffer Is Available Instead of Waiting for
the Entire Packet to Be Buffered
D Provides Full VPI/VCI Support and Allows
for the Simultaneous Segmentation of
1023 Packets and the Simultaneous
Reassembly of 30720 Packets
D Byte-Wide Cell Interface Is Full Duplex and
Compliant to the ATM-Forum UTOPIA
Document
D Cell Interface Can Be Programmed to
Operate as Either a Physical (PHY)-Layer
Interface or as a ATM-Layer Interface
D Provides Reassembly Time-Out for an
Incoming Packet
D Provides a High-Priority Mechanism for
Transmitting Constant-Bit-Rate Traffic
D Provides Support for Transparent/Null AAL
description
The TNETA1570 is an asynchronous transfer mode (ATM) segmentation and reassembly (SAR) device with
a 64-bit peripheral component interconnect (PCI)-bus interface. This device incorporates ATM adaptation-layer
(AAL) processing, ATM SAR processing for full-duplex operation up to STS-3c rate of
155.52 Mbit/s, and the controls for the register interface on the PHY layer. The device provides complete
encapsulation and termination of AAL5 packets in hardware.
The TNETA1570 supports high-speed networking applications utilizing ATM protocols as either a
backbone/backplane or desktop technology. Features include: high level of VPI/VCI support, high-priority
segmentation option for constant-bit-rate traffic, early buffer segmentation, buffer scatter/gather capability, and
32-/64-bit PCI-bus support.
The device contains an integrated 32-/64-bit PCI interface for transferring data and control information. The
segmentation and reassembly processes use host memory for storing packets that are transmitted or received.
No local-packet memory is required. The device is capable of segmenting up to 1023 packets simultaneously
and reassembling 30720 packets simultaneously. The device supports the full range of VPI/VCI values for both
transmit and receive operations.
The TNETA1570 also supports two methods of transporting a transparent/null AAL used for transferring
proprietary information. In addition, the device recognizes ATM-layer OAM cells and provides a mechanism for
handling these cells. The device contains a full-duplex, byte-wide cell interface compliant to the ATM-Forum
UTOPIA specification. The cell interface can be programmed to operate as either a PHY-layer interface or a
ATM-layer interface.
The integrated PCI-host interface operates as either a 32-bit or 64-bit interface for DMA operations. The device
operates as a 64-bit interface if the target device can accept 64-bit transfers; otherwise, it operates as a 32-bit
interface. The PCI-host interface provides both master and slave capability and operates at a frequency up to
33 MHz. The PCI-host interface is functionally compliant to the PCI-local-bus specification revision 2.0. The
TNETA1570 operation is explained in detail in the Principles of Operation section.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright  1996, Texas Instruments Incorporated
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