The XR16C854 *1 (854) is a universal asynchronous receiver and transmitter (UART) with a dual foot print interface compatible with the ST16C554D/654 and ST68C554/654. The 854 is an enhanced UART with 128 byte FIFOs, Independent Transmit and Receive FIFO counter, 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 854 is available in 64 pin TQFP, 68 pin PLCC, and 100 pin QFP packages. The 64 pin package offers the 16 interface mode which is compatible with the industry standard ST16C554. The 68 and 100 pin packages offer an additional 68 mode which allows easy integration with Motorola, and other popular microprocessors. The XR16C854CV (64 pin) offers three state interrupt control while the XR16C854DV provides constant active interrupt outputs. The 64 pin devices do not offer TXRDY/RXRDY outputs or the default clock select option (CLKSEL). The 100 pin packages offer faster channel status access by providing separate outputs for TXRDY and RXRDY, offer separate Infrared TX outputs and a musical instrument clock input (MIDICLK). The 854 combines the package interface modes of the 16C554/654 and 68C554/654 series on a single integrated chip.