PMC Sierra Corrects and Replaces Previous Release To Correct Stock Symbol.

VANCOUVER, British Columbia--(BUSINESS WIRE)--Oct. 6, 1997--

PMC-Sierra Introduces Industry's Most Highly Integrated

Sonet/SDH-Framer With Unique On-Chip Packet-Over-Sonet Interface;

The SPECTRA-155 Enables New Classes of WAN And Internet Equipment

to Improve Backbone Bandwidth Limitations

PMC-Sierra today announced the PM5342 SPECTRA-155, the industry's most highly integrated SONET/SDH framer and first available in the merchant market with a Packet-Over-SONET interface.

The SPECTRA-155 features on-chip OC-3 clock recovery, clock synthesis, SONET/SDH framing and an extensive array of mappers for Packet-Over-SONET, Frame Relay, ATM and T3/T1 Telecom options (see figure 1 and 2). The device enables new classes of high speed, standards-compliant WAN and Internet infrastructure equipment for both datacom and telecom applications such as the total integration of a SONET/SDH aggregate card.

Packet-Over-SONET is an emerging protocol for carrying IP and other data traffic over the SONET/SDH backbone network by mapping data packets directly into the SONET/SDH payload. Packet-Over-SONET seeks to allow the highest possible utilization of the SONET PAYLOAD. The SPECTRA-155's Packet-Over-SONET interface provides a cost-effective, SONET/SDH standards-compliant solution for high-speed routers and fast ethernet switches requiring 155 Mbit/s WAN backbone and Internet connections.

For datacom applications such as Frame Relay or ATM that require sub-155 Mbit/s WAN backbone connections, the SPECTRA-155 also features an extremely flexible on chip mapper array. This array supports ATM, Frame Relay and Point-to-Point Protocol (PPP) by enabling 45 Mbit/s HDLC or ATM to be mapped into SONET/SDH T3 tributaries. The SPECTRA-155 seamlessly interfaces with PMC-Sierra's FREEDM family of HDLC controller products to form the core of a series of Frame Relay over SONET/SDH cards.

For SONET/SDH public network equipment, the standards-compliant SPECTRA-155 features an on-chip Pseudo Random Bit Sequence (PRBS) generator and receiver. System side interfaces allow testing during installation and ongoing line quality monitoring to enable increased system control and diagnostics. The device implements a flexible telecom bus interface as referenced in IEEE proposal P1396 that supports serial, nibble or byte based transactions. The SPECTRA-155 connects seamlessly to PMC-Sierra's TUPP-Plus, TUDX, and D3MX to form the basis for the most integrated form factor for SONET/SDH add-drop muxes, terminal muxes and cross connects.

The PM5342 SPECTRA-155 is sampling now in a 256 BGA package and priced at $189 in 1KU quantities. The SPECTRA-155 is SONET/SDH compliant to the ANSI T1.1.05, Bellcore GR-253, ITU G.707 and ITU G.781 standards. A comprehensive support package is available which includes a technical overview, datasheet and reference design for Packet-Over-SONET applications.

"The SPECTRA-155 is PMC-Sierra's third generation SONET/SDH framer," said Tim Pezarro, marketing manager of ATM and SONET/SDH product at PMC-Sierra. "Our extensive SONET/SDH track record coupled with our datacom expertise enables us to create the most highly integrated, standards-compliant catalogue OC-3 solution equipped with the latest features the networking industry demands."

The SPECTRA-155 and PMC-Sierra's complete line of high speed networking solutions will be on display in Booth No. 8651 at the NETWORLD+INTEROP trade show in Atlanta, Georgia, October 8 through 10.

PMC-Sierra is a leading provider of high speed internet working component solutions emphasizing ATM, SONET/SDH, T1/E1 and Ethernet applications. The company's quality system is registered with the Quality Management Institute to the ISO 9001 standard. As co-founder of the SATURN Development Group, PMC-Sierra works with over 40 other member companies to define and develop interoperable, standard-compliant solutions for high speed networking applications.

Headquartered near Vancouver, British Columbia, PMC-Sierra also offers local technical and sales support in California, North Carolina, Massachusetts, Texas, Europe and Asia. The company is traded on the Nasdaq National Market under the symbol "PMCS". In Beaverton, Oregon, the company has established an Ethernet Products Division focused on developing leading edge Ethernet semiconductor solutions. PMC-Sierra is located on the World Wide Web at http://www.pmc-sierra.com .

Technical Backgrounder on the PM5342 SPECTRA-155

The SPECTRA-155 is a single chip solution for OC-3 clock recovery, synthesis, framing, and mapping and was built upon PMC-Sierra's extensive expertise in mixed signal integrated circuit design. The SPECTRA-155 is PMC-Sierra's third generation SONET/SDH framer which incorporates new features which are ideal for use in today's high performance telecom and datacom applications.

The SPECTRA-155 complies to the latest SONET/SDH standards for use in add-drop mux, terminal mux and cross-connect equipment. The device also incorporates a new SONET/SDH payload mapper/extractor and Packet-Over-SONET interface for use in new high speed routers and frame relay switches.

The SPECTRA-155 is packaged in a 256 Super BGA (Ball Grid Array) package and supports industrial temperature range (-40 degrees C to 85 degrees C) operation. The simplified block diagram of the SPECTRA-155 is shown in Figure 1.

The line interface module provides high-speed 155 Mbits/S PECL (pseudo-ECL) outputs that directly interface to optical modules. The clock synthesis unit generates a 155.52 Mbits/S (STS-3 or STS-3c) or a 51.84 Mbits/S (STS-1) clock from a reference signal of 19.44 MHz.

The clock synthesis unit meets Bellcore and ITU jitter standards requirements. The integration of the clock recovery and synthesis allows for increased board densities and decreases design complexity by reducing the need for additional external high-speed clock circuitry.

The transmit/receive overhead processors terminate the SONET/SDH section, line and path overhead streams. These processors perform SONET/SDH overhead framing, overhead byte insertion/extraction, and bit interleaved parity (BIP) error generation/detection. In addition, the SONET/SDH processors support section and path trace, automatic protection switching (APS), and tandem connection for improved SONET/SDH system reliability and monitoring. The SONET/SDH processors provide standards compliance to ANSI T1.105, Bellcore GR-253, ITU G.707, and ITU G.781.

The SPECTRA-155's SONET/SDH payload mapper/extractor arrays provide Packet-Over-SONET capability. Packet-Over-SONET is an emerging protocol for carrying IP and other data traffic over the SONET/SDH backbone network. Packet-Over-SONET seeks to allow the highest possible utilization of the SONET payload.

However, mapping packets directly into the SONET payload exposes the system to the danger of a "killer packet" which is a particular SONET payload pattern which causes all SONET framers to lose synchronization. To eliminate this threat, the SPECTRA-155 Packet-Over-SONET mappers scramble the payload data using an X^43+1 self-synchronous scrambler.

All data passing through the scramblers is "safe" and will not cause the framers to lose synchronization. On the receive side, the extractors apply the same polynomial to unscramble and recover the original data. Optionally, the mapper/extractor may be bypassed allowing direct SONET payload access.

The SPECTRA-155's system side interface supports a wide variety of telecom and datacom interfacing options. The system interface supports the Telecombus interface as referenced in IEEE proposal P1396 and supports serial, nibble, and byte-based transactions. The system interface also features a bit serial DS-3 clock and data interface for datamode mapping.

For increased system control and monitoring, the SPECTRA-155 also features system and line side loopbacks for fault isolation. Also, the 23-bit PRBS (pseudo random bit sequence) generator and receiver can insert test into the transmit stream during system operation and can automatically monitor for correct reception of this data.

The SPECTRA-155 provides the high-speed hardware functionality for OC-3/STM-1 interface cards for both telecom and datacom WAN infrastructure and LAN extension applications. The SPECTRA-155 connects seamlessly to the PM5362 TUPP-PLUS forming the major hardware functionality of an OC-3/STM-1 aggregate interface for SONET/SDH add/drop muxes, terminal muxes.

Optionally, the PM5371 TUDX can be added to provide the hardware functionality for a SONET/SDH cross-connect. For new Packet-Over-SONET applications, the SPECTRA-155 can also form the high-speed interface for a Packet-Over-SONET WAN card.

The SPECTRA-155 defines the next generation of SONET/SDH framers. From compliance to the most recent SONET/SDH framing standards to the flexible mapper array which includes Packet-Over-SONET support, the SPECTRA-155 provides features which are critical to designers who are working on the latest WAN backbone equipment. The SPECTRA-155 is the newest addition to PMC-Sierra's broad portfolio of networking solutions. -0-

Note to Editors: Detailed graphics are available upon request. Contact Sue Shaw at 604/415-6031 or Mary Beth Deline at 604/415-6096, or visit http://www.pmc-sierra.com .

CONTACT: PMC-Sierra

Susan Shaw, 604/415-6031

[e-mail]

or

Strategic Press Relations

Dan Garza, 408/733-4669

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Publicity Management (European editorial)

Leslie Franks, [phone]