Emerald-MM-8Plus is a high performance multi-protocol serial communications board offering eight ports on a single PC/104-Plus module. Supporting baud rates up to 921.6K bps in RS-232 mode or 1.8432Mbps in RS422 or RS485 mode, each port can be individually selected for RS-232, RS-422, RS-485 or TTL level operation. Both local-echo and non-local-echo modes are supported for RS-485. Protocol selection is achieved via a jumper block for each of the eight ports. Line termination for RS-422/485 modes is also jumper-selectable.
Configuration of the Emerald-MM-8Plus is simple, using the built-in plug and play technology. For manual configuration, the base address for the board may be set in software, defining a 4K block of configuration space used to access the on-board registers. A single 32-bit read shows the detailed interrupt status for each of the eight ports. The PCI “slot” is defined through a jumper block. As with all Diamond Systems products, jumpers are paralleled with locations for zero ohm resistors to create a rugged, shock-and- vibration-resistant implementation.
Emerald-MM-8Plus is based on the Exar 17D158 octal UART IC. This device contains 8 4 identical sets of 16C55registers, one for each port, and is compatible with the standard PC serial port. Each port contains 64-byte transmit and receive FIFOs to support the high-speed data rates.
Emerald-MM-8Plus also offers 8 convenient digital I/O lines. The direction of each line is independently programmable. Finally, Emerald-MM-8Plus also offers a 16-bit programmable counter / timer with a configurable clock source.
Two I/O headers are provided, with four serial ports and four digital I/O lines on each header. The board operates on +5V only, eliminating the need for a +12V supply that is often required for serial port operation.
Operating Systems Compatibility
The Emerald-MM-8Plus is compatible with Windows 98/NT/2000/XP and Linux. If using Exar's default Vendor and Device ID, you can use Exar's module driver for Linux kernels 2.4.x and Linux kernels 2.6.1-2.6.7. Linux kernels 2.6.8 and newer have support in the kernel for the XR17x15x PCI UARTs. See the "8250_pci.c" in the kernel. If using your own Vendor and Device ID, you can use the module driver available from Exar after you modify the Vendor and Device ID accordingly in the module driver.