Background Information: Communications Technology
Background Information: Communications Technology
In recent years, there has been a growing awareness of the importance of communications technology, in applications that range from global networks to high speed serial interconnects at the chip level. Building on its long tradition of success in the telecomms market, SGS-THOMSON has positioned itself to be among the key players in the market for advanced communications products in areas such as GSM, ATM, high speed modems and packet switches.
GSM While GSM is a major sector of the digital cellular telephony, this market will also include PDAs, multimedia terminals and high end executive phones as well as low cost handheld phones. This fragmentation of the market favours ASIC rather than standard chip solutions for the key functions such as the baseband controller. SGS-THOMSON's GSM strategy is to form partnerships with world-wide leaders in the equipment field and to supply a complete kit of macrofunctions, from DC to RF.
At the heart of a GSM receiver is the baseband controller, which has to handle Layer 1 functions such as speech coding, channel processing, interleaving and encryption/decryption, GMSK modulation and timing and sequencing control. The baseband controller may also be required in addition to handle upper layers, using software running on an integrated MCU.
SGS-THOMSON's solution is a semicustom baseband controller using our 0.5um ASIC library. This contains all of the functions required, including 16-bit DSP and MCU cores, each of which occupies less than 10 sq. mm of chip area. The C16x-CORE is the MCU core from the high performance ST10 family, while the D950-CORE provides 40MIPS performance that can easily handle the computational demands of GSM.
Another important GSM function is voice encoding and decoding,an area where we combine a proven design expertise with excellent CMOS and BiCMOS technologies. The ST5090, for example, is a standard linear 14-bit voice codec particularly suited to any digital phone including all TDMA (GSM, DAMPS, JDC) and CDMA mobile terminals where it supports all tones and DTMF generation and eliminates all glue logic between the microphone, earpiece and buzzer. We can also now offer custom integration of all ADC and DAC functions needed in a multistandard TDMA mobile receiver (GSM/DAMPS/JDC), together with custom logic and the DSP core.
For the Subscriber Identification Module (SIM), our ST16SF44/48 smartcard ICs based on the popular ST16XYZ CPU core is ideal. The devices offer 16kbytes of ROM, 384 bytes of RAM and 4k/8kbytes of EEPROM, respectively.
GSM is a major user of FLASH and EEPROM memories, so our strength in non-volatile memories is of particular value. We have a growing presence in the FLASH memory market and we also supply 64kbit serial EEPROMs that offer a greatly reduced package size compared to the 64kbit parallel EEPROMs that have been used to date.
ATM Providing a common switching technology for both local and wide area networks, ATM is expected to replace Ethernet as the dominant networking protocol in the coming decade. In an ATM network, data streams are divided into blocks of 48 bytes and a 5-byte header, containing the information required to route the cell to its intended destination, is appended to each block to form a 53-byte ATM cell. Cell streams are switched through the network in accordance with the routing information contained in each cell. At the receiving station, the headers are discarded and the 48-bit cell payloads are then reassembled to recreate the original message.
As a major supplier of Ethernet and other datacommunication controllers, SGS-THOMSON has a strong interest in the emerging ATM market and a major development programme is in place, involving dedicated leading edge products, macrocell libraries, applications support and alliances with key customers.
The ATM physical layer and interconnect requires very high speed combined with low power consumption. Our 3V/0.5um CMOS and 5V/0.7um BiCMOS technologies are already well able to meet these requirements but migration to the 3V/0.5um BiCMOS and 3V/0.35um CMOS processes that are being developed is also planned.
For the cell processing, management and control functions, the speed requirements are relaxed but low power dissipation remains a key requirement and we also need very high density integration. For these functions, our 0.5um CMOS ASIC technology is ideal, offering 200MHz operation, 0.7uW/MHz/gate power dissipation, triple metal stacked via layout and gate densities of up to 7 kgates/sq.mm.
In addition to the dedicated ATM circuits that are currently being sampled or developed, we are also offering macrocells that implement functions such as line termination, ATM cell processing or IEEE P1355 serial links.
Modems and datacommunications ICs SGS-THOMSON offers a range of single- and multi-chip modem devices such as the ST75C50x/ST754x combinations aimed at the market for V.32bis data and V.17 fax modems. These standards support data rates from 7,200 up to 14,400 BPS and their use in the portable/handheld PC business is expected to increase over the next few years.
The ST75C50x is built around a powerful DSP core - the same core that currently powers major customer applications such as GSM phones, Global Positioning System (GPS) receivers, multimedia PC cards and minidisk players. The ST75C50x also contains a large 16kx32 on-chip program memory, an 8kx16 ROM, a 4kx16 RAM and three double-buffered synchronous serial interfaces which allow direct connection - without additional glue logic - to the ST754x Modem Analogue Front Ends.
These chipsets also offers a simple upgrade path to the 28,800 BPS V.34 (V.FAST) standard. In addition, SGS-THOMSON is able to offer complete "turn-key" solutions such as the SATURN (System Adaptable TURN-key) board, together with modem protocol software (V.42bis/MNP5, Fax Class1-2).
In the field of data communications controllers, SGS-THOMSON's portfolio includes the MK50H28 Frame Relay controller as well as X.25, ISDN LAPD and SS#7 link layer controllers. The Frame Relay protocol is being increasingly used instead of X.25 in routers and hubs. The MK50H28 has full duplex data throughput up to 13Mb/s in protocol mode - so fast, it allows customers to take advantage of Frame Relay at T1, E1 and fractional T3 data rates.
High Speed Interconnects Fibrechannel, switched Ethernet/Token Ring and other communications nodes, massively parallel supercomputers, disk arrays, next generation mainframe computers and video server applications such as Video-on-Demand delivery systems are all important applications that require flexible, scalable, high speed communications networks.
SGS-THOMSON's flagship devices in this area are the STC101 Parallel DS-link Adaptor and the STC104 Asynchronous Packet Switch. These allow networks of arbitrary size and configuration to be constructed and let multiple 10Mbyte/s data streams to be routed concurrently and independently through the network. These devices are based on the DS-link serial protocol which was developed by SGS-THOMSON and is now being adopted by the IEEE as part of an international standard.
The STC104 is a complete asynchronous packet switch on a single chip, with 32 DS-link inputs, 32 DS-link outputs and a 32 x 32 crossbar that allows datastreams to be routed through the chip from all inputs to all outputs simultaneously, giving a peak bandwidth of 300Mbyte/s for a single chip. In addition, each input link has its own programmable routing engine that is fast enough to process a continuous stream of data packets without bottlenecks, allowing the chip to handle more than 200 million packets per second.
Security One of the most important topics in data communications networks today is data link security. Public Key cryptography, which allows 'electronic signatures' to be attached to messages, is therefore a technique of growing importance. With its single-chip cryptocomputers, its Crypto Manager firmware (which greatly simplifies and accelerates product development) and its customer-orientated approach to security and security evaluaton, SGS-THOMSON is a world leader in this critical area.
Across the spectrum of communications applications, semiconductor manufacturers are being asked to provide solutions that meet ever increasing performance targets at competitive costs. With its portfolio of advanced technologies and alliances with major customers such as Alcatel, France Telecom and Northern Telecom, SGS-THOMSON has the vision and the capability to be a leading player in this area.