SCC68681C1N40,112

UARTs (Universal Asynchronous Receiver Transmitter) Overview

The NXP USA Inc. SCC68681C1N40,112 is a Dual Universal Asynchronous Receiver/Transmitter (DUART) manufactured in a CMOS process. It provides two independent full-duplex asynchronous receiver/transmitter channels within a single package. The device features quadruple buffered receiver data registers to minimize overrun potential and reduce interrupt overhead. Each channel supports programmable data formats including 5 to 8 data bits plus parity, with 1, 1.5, or 2 stop bits. Baud rates are selectable from 22 fixed rates ranging from 50 to 115.2 kbaud, non-standard rates up to 115.2 kb, or external clocks. Maximum data transfer rates reach 1 MB/sec at 1× clock and 125 kB/sec at 16× clock. It includes a 16-bit programmable counter/timer, error detection capabilities, and operates on a single +5 V power supply.

UARTs (Universal Asynchronous Receiver Transmitter) Feature Summary

• S68000 bus compatible architecture for seamless integration with microprocessors
• Independent programming of operating modes and data formats for each channel
• Quadruple buffered receiver data registers to prevent data loss during high-speed transfers
• Versatile interrupt system with maskable conditions and vector output capability

UARTs (Universal Asynchronous Receiver Transmitter) Applications

• Polled or interrupt-driven communication systems
• Dual-speed channel applications such as clustered terminal systems
• Multidrop network environments requiring automatic wake-up mode
• Systems requiring hardware flow control via RTS/CTS signals

UARTs (Universal Asynchronous Receiver Transmitter) Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm temperature range and package type. The 'C' designation indicates commercial temperature range (0 °C to +70 °C), while 'E' denotes industrial range (-40 °C to +85 °C). Ensure the DIP40 package variant matches the required PCB footprint. Confirm RoHS compliance status if environmental regulations apply to the end product assembly.

UARTs (Universal Asynchronous Receiver Transmitter) Selection Notes

Select this component when S68000 bus compatibility is required alongside dual-channel asynchronous communication. Consider the quadruple buffering feature for applications demanding reduced CPU interrupt overhead. Evaluate the need for independent baud rate generation per channel, which supports diverse peripheral speeds. Verify that the available I/O ports meet the system's general-purpose input/output requirements without additional logic gates.

UARTs (Universal Asynchronous Receiver Transmitter) Part Context

The SCC68681 is part of the Philips Semiconductors (now NXP) DUART family, designed primarily for the Motorola 68000 processor ecosystem. It serves as a dedicated communications interface solution, replacing discrete UART components. The device integrates timing, control, and I/O functions into a single MOS-LSI chip, simplifying board layout and reducing component count in embedded controller designs.

UARTs (Universal Asynchronous Receiver Transmitter) Replacement Considerations

Direct pin-compatible replacements include the Exar XR68C681 series. Verify register mapping and electrical specifications before substitution. Alternative solutions may require software adaptation due to differences in interrupt handling or mode register definitions.