The XR16C2850 (2850) is a dual universal asynchronous receiver and transmitter (UART). The 2850 provides enhanced UART functions with 128 byte FIFO, automatic RS-485 half duplex control, a modem control interface, and data rates up to 1.5 Mbps. Onboard status registers provide the user with error indications and operational status. System interrupts and modem control features may be tailored by external software to meet specific user requirements. An internal loopback capability allows onboard diagnostics. Independent programmable baud rate generators are provided to select transmit and receive clock rates up to 1.5 Mbps. The baud rate generator can be configured for either crystal or external clock input. The 2850 is available in a 40-pin PDIP, 44-pin PLCC, and 48-pin TQFP packages. The 40 pin package does not offer TXRDY and RXRDY pins (DMA Signal monitoring). Otherwise the three package versions are the same. The 2850 is functionally compatible with the ST16C2550. The 2850 is fabricated in an advanced CMOS process to achieve low drain power and high speed requirements.