DESCRIPTION

The XR68C92/192 is a Dual Universal Asynchronous Receiver and Transmitter with 8 (XR68C92) or 16 (XR68C192) bytes of transmit and receive FIFOs. The XR68C92/192 is pin-to-pin and functionally compatible to the XR68C681 and Philips SCC68681 UART with additional features. The operating speed of the receiver and transmitter can be selected independently from a table of twenty four fixed baud rates, a 16X clock derived from a programmable counter/ timer, or an external 1X or 16X clock. The baud rate generator and counter/timer can operate directly from a crystal or from external clock input. The XR68C92/192 provides a power down mode in which the oscillator is stopped but the register contents are retained. The XR68C92/192 is fabricated in an advanced CMOS process to achieve low power and high speed requirements.

FEATURES

• Pin to pin and functionally compatible to XR68C681 and SCC68692

• Full duplex transmit and receive operation

• 8 bytes of transmit/receive FIFOs (XR68C92)

• 16 bytes of transmit/receive FIFOs (XR68C192)

• Programmable character lengths (5, 6, 7, 8)

• Parity, framing, and over run error detection

• Programmable 16-bit timer/counter

• On-chip crystal oscillator

• Single interrupt output with eight selectable interrupting conditions

• External 1X or 16X clock

• Data rate up to 1Mbps

• Independent transmit and receive baud rates from 50bps to 230.4kbps

• 6 General purpose inputs

• 8 General purpose outputs

• TTL compatible inputs, outputs

• 4 Transmit/receive trigger levels

• Watch dog timer

• Multi-drop mode compatible with 8051 nine bit mode

• 3.3 or 5 volts operation

• Loopback modes

• Power down mode