The XR16C8641 (864) is a universal asynchronous receiver and transmitter (UART) with a dual interface compatible with the ST16C554/654/854 and ST68C554. The 864 is an enhanced UART with 128 byte FIFO's, Independent Transmit and Receive FIFO counters, RS-485 Support, Independent Transmit and Receive DMA signals, automatic hardware/software flow control, and data rates up to 1.5Mbps. Onboard status registers provide the user with error indications and operational status, modem interface control. System interrupts may be tailored to meet user requirements. An internal loop-back capability allows onboard diagnostics. The 864 is available in 100 pin QFP packages. The XR16C864 offers faster channel status access by providing separate outputs for TXRDY and RXRDY, offer separate Infrared TX outputs and a separate clock for channel C (CHCCLK) that can be used as a musical instrument clock input. The 864 combines the package interface modes of the 16C554/654 and 68C554/654 series on a single integrated chip.