The XR68C681J is a Dual Universal Asynchronous Receiver/Transmitter (DUART) manufactured by Exar Corporation. It provides two independent full-duplex asynchronous communication channels. It is designed to interface with a wide range of microprocessors and microcontrollers, offering a flexible solution for serial communication needs.

Applications:

• Serial communication ports for embedded systems
• Modems and other communication devices
• Industrial control systems
• Data acquisition systems
• Multi-port serial interfaces

Features:

• Two independent full-duplex UART channels
• Programmable baud rate generator for each channel
• 5, 6, 7, or 8 data bits
• Even, odd, or no parity
• 1, 1.5, or 2 stop bits
• Modem control signals (CTS, RTS, DSR, DTR, RI, DCD)
• Interrupt generation on receiver ready, transmitter ready, and error conditions
• Local and remote loopback modes for diagnostics

Benefits:

• Versatile serial communication: Supports a wide range of baud rates and data formats.
• Reduced system complexity: Integrates two UART channels into a single chip.
• Improved system performance: Hardware-based UARTs offload serial communication tasks from the CPU.
• Flexible interrupt handling: Programmable interrupt generation allows for efficient handling of serial communication events.
• Easy integration: Compatible with a wide range of microprocessors and microcontrollers.

Additional Details:

The XR68C681J provides a complete serial communication solution, including baud rate generation, data formatting, and error detection. It supports a variety of interrupt modes, allowing for efficient handling of serial communication events. The modem control signals enable interfacing with external modems and other communication devices. The device is typically packaged in a DIP (Dual In-line Package) or PLCC (Plastic Leaded Chip Carrier).

Electrical Specifications:

• Operating Voltage: 5V
• Baud Rate: Programmable, up to 1 Mbps (check datasheet for precise values)
• Data Bits: 5, 6, 7, or 8
• Parity: Even, odd, or no parity
• Stop Bits: 1, 1.5, or 2