Tech Specs:

  • Measures 3.6 x2.3×0.3 inches
  • Can be driven by Engine controllers.
  • Two QUARTs (TL16C754B), 8 UARTs total
  • 64 byte FIFO buffer for each UART
  • Hardware or software flow control
  • Low power mode, high speed data rate
  • On-board RS232 drivers.
  • Can also be configured as RS485/RS422/TTL.

Similar expansion boards: None
Supported controllers: All

General Info

The UART8 (UR8) is an expansion card designed to easily add 8 serial ports to any TERN controller, making the units even more flexible for a whole range of new applications that have high serial communication needs.

Two QUART chips (TL16C754B, TI) are installed on the U8. The TL16C754B is a quad universal asynchronous receiver and transmitter (UART) with 64 byte hardware FIFOs, automatic flow-control, and high-speed data rates.

The deep 64-byte transmit and receive buffers releases processor load and helps guarantee reliable performance for multi-serial port high-speed communication.

The QUART also offers other enhanced features. It has a transmission control register (TCR) that stores received FIFO threshold level to start/stop transmission when using flow ocntrol.

With a single FIFO RDY register, software can access FIFO status for all channels in one access. On chip status registers provide error indication, operation status, and modem interface control. An internal loop-back capability allows on-board diagnostics. The QUART supports 5, 6, 7, or 8-bit serial communication.

The QUART can be programmed to generate a desired baud rate by using a programmable divisor, and installed input clock. By default, a 3.6864 MHz crystal is installed to provide the clock input. Up to 50 MHz clock input can also be used. The QUART can receive even, odd, or no parity… as well as handling various stop-bit configurations. 4 UARTs have RS232 drivers, without handshaking signals, and can be configured as TTL level signals.

Another 4 UARTs have RS232 drivers with hardware handshaking supported by default. This second set of 4 UARTs can be configured as RS485, and one of them can also be configured with 4-wire RS422 drivers.

All other handshaking or modem control signals are TTL level and routed to two-20×2 pin headers, and they can also be used as general programmable TTL I/Os in your embedded application. The UR8 can be installed and interface to TERN controllers via J1 8-bit data bus.

There are voltage-shifting circuits on board, allowing connecting the UR8 to a 5V or a 3.3V processor, such as 586- Engine. The UR8 is powered by external regulated 5V via J1 or J2 connector.

If you’re interested in other TERN controllers providing multiple serial communication ports, be sure to look at the FlashCore-N and the A104-S.


Includes two QURTs, 8 total RS-232 channels (4 w/ hardware handshaking support).

Add-on Options

  1. Modification to drive RS485/RS422/TTL signals

Related Products