The ST16C2550 (2550) is a dual universal asynchronous receiver and transmitter (UART). The ST16C2550 is an improved version of the NS16C550 UART with higher operating speed and lower access time. The 2550 provides enhanced UART functions with 16 byte FIFOs, a modem control interface, and data rates up to 1.5Mbps. 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 from 50 Bps to 1.5 Mbps. The Baud rate generator can be configured for either crystal or external clock input. The 2550 is available in a 40-pin plastic-DIP, 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 2550 is functionally compatible with the 16C2450. The 2550 is fabricated in an advanced CMOS process to achieve low drain power and high speed requirements.