The XR16L570 (L570) is a 1.62 to 5.5 volt Universal Asynchronous Receiver and Transmitter (UART) with 5 volt tolerant inputs and a reduced pin count. It is software compatible to industry standard 16C450, 16C550, ST16C580, ST16C650A, XR16C850 and XR16L580 UARTs. It has 16 bytes of TX and RX FIFOs and is capable of operating with a serial data rate of up to 4 Mbps at 5V, 3 Mbps at 3.3V,1 Mbps at 2.5V and 750 Kbps at 1.8V. The internal registers are compatible to the 16C550 register set plus enhanced registers for additional features to support today's high bandwidth data communication needs. The enhanced features include