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EXAR Introduces 1st 4-Channel 64 Byte FIFO UART Family

Monday, June 2, 1997

Fremont, CA, June 2, 1997. . . . . EXAR Corporation (NASDAQ: EXAR) announced today the availability of the first family of 64-byte FIFO Universal Asynchronous Receiver Transmitter (UART) devices for a wide variety of serial-to-parallel and parallel-to-serial connections.

The ST16C654 is a four-channel device supporting Intel or Motorola bus interfaces. It is designed for use in a wide variety of multi-channel serial communication applications, such as network servers, remote access Internet servers, high-speed modems, ISDN adapters, industrial control systems and test equipment.

This is the latest addition to the existing family of UART, DUART and QUART from EXAR in various packages, including 16-byte and 32-byte FIFO configurations. This represents the most complete family of UART solutions in the market.

Technical Description

This is the first four-channel device to offer 64 bytes of transmit and receive FIFOs, instead of the industry standard 16 bytes. This reduces the CPU interrupt service intervals, and increases overall system performance, by allowing greater amounts of data to be transferred during each interrupt service.

In addition, automatic hardware RTS (request-to-send) and CTS (clear-to-send) and software flow control Xon and Xoff, or two sequential special characters, help prevent data error, optimize throughput and further reduce software overhead on the host processor, thereby freeing up valuable bandwidth.

Furthermore, when operating with a 14.7456 MHz crystal, a software selectable clocking scheme allows standard data rates of up to 460.8 and 921.6 Kbps, giving users the ability to support new higher-speed modems and improved data speed in inexpensive serial networks.

Like other products in the existing families of EXAR UART devices, the ST-16C654 is pin- and software-compatible with the industry standard ST-16C554 UART for easy upgrade of existing systems. The device also has very low operating power of typically 8mA, with sleep mode of 200uA, for reduced power consumption, longer battery life and reliability.

According to Kumar Bhatia, President and Co-founder of Axxon Computer Corporation of Ontario, Canada, "The 16C654 UART used on our Quadport, provides the necessary advanced features of 64 Byte FIFOs, higher baud rates and Auto Flow Control while allowing us to be competitive."

According to Sun-Man Lo, Strategic Marketing Manager at EXAR, "We feel the 654 provides the best data throughput of any existing UART products on the market, which results in higher performance characteristics for our customers and their customers. We see this as a logical extension to our existing UART family."

Price and Availability

The entire ST-16C654 family is fabricated in 68-pin PLCC, 64-pin TQFP and 100-pin TQFP packages. It is also available in commercial and industrial temperature ranges. Production samples are available now with prices from $10.00 to $12.00 in high volume, depending on configuration.


EXAR Corporation (NASDAQ:EXAR) designs, develops and markets innovative, system oriented analog and mixed-signal integrated circuits for video, imaging, communications and silicon sensing. For more information, contact the company at 48720 Kato Road, Fremont, CA 94538. Phone: (510) 668-7000.

Greg Kaufman
(510) 668-7121

Media Contact
Marketing Communications