2229 Technobox 8-Port Async Communication Adapter PMC Card

The Technobox 8-Port Async Communication Adapter PMC Card provides eight 16550-based UARTs using RS232 signaling levels.

Each port provides the full set of data and modem control lines configured for DTE (i.e., computer side) operation: RTS (Request to Send), CTS (Clear to Send), TXD (Transmit Data), RXD (Receive Data), DCD (Data Carrier Detect), DTR (Data Terminal Ready), DSR (Data Set Ready), and RI (Ring Indicator).

All eight ports are available out the PMC front panel via a 68-pin SCSI-style connector. Also, the ports are wired to the P4 connector at the rear of the PMC, allowing connection of all eight ports to the VMEbus P2 connector for host processors supporting rear-I/O connection.

A transition panel converts the 68-pin SCSI style connector into eight 9-pin male DSub-miniature connectors, which are pinned-out according to the Personal Computer standard.

For Rear I/O, a paddle card converts the P2 'a' and 'c' rows back into the 68-pin SCSI style connector. This permits use of the eight 9 pin DSub transition panel for rear-exit from the card cage.

The transition panel may also be mounted at any convenient point in a user's system.

The UARTs operate at standard baud rates from 300 baud to 115Kbaud.

The eight interrupt requests from each UART are routed to one of the four INTx lines on the PCI bus. This design avoids interrupt routing switches by incorporating a programmable element which can be set up from the host processor, allowing any UART to be routed to any INTx request line. The default after reset is all UART interrupt requests are routed to the INTA line.

The 16550 register set is accessed from the host processor using Programmed-I/O. "C" source code is provided with the board to illustrate how to set up the PCI bus bridge in order to access the UART registers. Once the registers are mapped into host I/O space, standard async communication drivers may be used to access the ports.