Emerald-MM-DIO

• 4 RS-232 serial ports
• Flexible address and interrupt selection
• 48 digital I/O lines
• Dual 20-pin I/O headers (2 ports per header) for serial ports

For users who need a higher level of integration than our standard products deliver, we offer this two-in-one board with 4 RS-232 serial ports, 48 digital I/O lines, and extended temperature operation.

Each serial port provides the standard set of PC serial port signals. The ST16C554 quad UART chip on board contains a 16-byte FIFO for each port and supports data rates of up to 115kbps. Interrupt sharing is fully supported among the four serial ports, and an interrupt status register enables the board to operate under Windows NT. Eight different address combinations are possible, and any of 11 different interrupt levels can be used.

The 48 digital I/O lines feature programmable direction on a line by line basis, and all lines have 10KOhms pull-up resistors. One group of 24 lines includes the additional feature of programmable edge detection. Both active line selection and edge polarity are programmable. Status registers indicate which, if any, lines have changed logic levels in the selected manner since the last status check. An interrupt can be generated on the PC/104 bus whenever the indicated activity occurs.