The MAX3110E/MAX3111E's UART includes a crystal oscillator and baud-rate generator with software-programmable divider ratios for all common baud rates from 300baud to 230kbaud. The UART features an 8word-deep receive FIFO that minimizes processor overhead and provides a flexible interrupt with four maskable sources. Two control lines (one input and one output) are included for hardware handshaking. The UART and RS-232 functions can be used together or independently since the two functions share only supply and ground connections (the MAX3110E/ MAX3111E are hardware- and software-compatible with the MAX3100 and MAX3222E).