Bridge chips simplify USB to serial connectivity

Intelligent USB to serial port bridge chips from Oxford Semiconductor provide serial port peripherals with the instant plug-and-play connectivity and high-speed data transfer of full-speed USB2.0. The single UART OXUSB950 and quad UART OXUSB954 feature an integral 12Mbps transceiver and serial interface engine and support baud rates up to 230kbps.

Supported by a complete set of royalty-free USB host device drivers, the bridge chips create transparent interfaces between USB and serial ports which require no firmware changes. For legacy applications, the OXUSB95x chips provide a simple means to upgrade peripherals from serial to USB communication. Power economy is assured by the integral USB suspend/resume function.

Handling USB transaction and control data processing is the bridge chip's advanced 16-bit micro-controller. Operating at 5MIPs and featuring 3Kbytes of on-board RAM and masked ROM, the controller also offers the flexibility and processing power to enable development of peripherals able to process data before it is passed to the host PC. The task optimisation this achieves further improves system performance.

An additional independent UART is provided for code development and debug. Supporting transmit and receive data rates up to 115Kbps, this UART can also be configured as an extra serial communications port. A universal E2PROM interface is a standard feature of both ICs and two multi-purpose GPIOs are offered by the OXUSB950. Packaging for the 3.3-volt OXUSB950 and OXUSB954 bridge chips is respectively 44-pin and 100-pin LQFP.