Product Information

The Technobox, Inc. P/N 5436 is a 16-Port Async Communication Adapter that features industry standard 16550-based UARTs using RS232 signaling levels. Each port provides a 4-signal functional subset of 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).

All sixteen ports are available out the PMC front-panel on J1 68-pin SCSI-style connector. They are also routed in parallel to the PN4 connector at the rear of the PMC, allowing connection to the VMEbus P2 connector for host processors supporting rear-I/O. These signals are carried on the “a” and “c” rows on the P2 connector. There are other standard connection configurations for the P0/J0 (enhanced VME and cPCI) and the “d” and “z” rows of an enhanced DIN connector.

The UARTs operate at standard baud rates from 300 baud to 115K-baud. Other odd-baud rates are possible and are available on special order. The UART IC used is a 16C554, which contains four independent 16550 UARTs. The bridge between the 16550-register set and the PCI bus is a PLX 9030 chip this is a slave only device so all access from the host processor is done through programmed I/O to the PCI bus I/O space, as is customarily done for Asynch communication software. Once the registers are mapped into host I/O space, standard Async communication drivers may be used to access the ports. “C” source code is provided with the board to illustrate how to set up the PCI bus bridge to access the UART registers.