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Octal UART cranks out 8 Mbps

Jan 30, 2006 — by LinuxDevices Staff — from the LinuxDevices Archive — 6 views

Exar has added an eight-channel, 8 Mbps octal UART to its serial communications chip line. The XR16V798 ups the ante on serial data communications speeds in embedded and industrial applications such as remote access servers, network management, factory automation, and point-of-sale systems, according to the company.

According to Exar Marcom Manager Greg Kaufman, other companies offer faster UARTs, but probably not with eight channels. “There are other 8Mbps UARTs out there. Ours, as an 8-channel, may be one of the first.”

According to Kaufman, the UART chip can be used “any place you've got parallel and serial data converting, or vice versa.” Applications include industrial control, bar-code readers, and increasingly, mobile consumer devices with serially attached peripherals, such as mobile phones and PDAs. “Consumer devices, where voltage and battery power are so important, is a new area for us, but we recently announced a 1.8-volt part in a small package.”

The XR16V798 is a 2.25V to 3.6V chip with 5V tolerant inputs. Exar lists the following additional key features and specs for the chips:

  • Up to 8 Mbps serial data rate
  • 64-byte transmit (TX) and receive (RX) FIFOs with fully programmable trigger levels
  • Fractional baud rate generator
  • Automatic RTS/CTS or DTR/DSR hardware flow control with programmable hysteresis
  • Automatic software (Xon/Xoff) flow control
  • RS-485 half-duplex direction control with programmable turn-around delay
  • Sleep mode with wake-up indicator
  • Global interrupt source register for all 8 UARTs
  • General purpose command-driven 16-bit timer/counter
  • Standard 8-bit Intel or Motorola data bus interface
  • -40 to +85 degrees C “industrial temperature range” operation

The chip implements the industry standard 16C550 register set, so it supports standard operating systems, including embedded Linux.

XR16V798 block diagram
(Click image for larger view)

“At 8Mbps, the XR16V798 breaks new ground for Exar and offers customers the best overall solution to quickly react to the rapid time-to-market demands of next generation industrial applications,” said Eric Nguyen, senior strategic marketing manager, Interface Products Division.


The XR16V798 is available now in 100-pin QFP packages at $20.13 for 1,000 pieces, according to the company.

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