General Description
The a8251 MegaCore function provides an interface between a  microprocessor and a serial communications channel. The a8251 receives  and transmits data in a variety of configurations including 7- or 8-bit data  words, with odd, even, or no parity, and 1 or 2 stop bits. The transmitter  and receiver can be designed for synchronous or asynchronous operation.

Features
■ a8251 MegaCore function that provides an interface between a  microprocessor and a serial communication channel
■ Optimized for FLEX® architecture
■ Programmable word length, stop bits, and parity
■ Offers divide-by-1, -16, or -64 mode
■ Supports synchronous and asynchronous operation
■ Uses approximately 528 FLEX logic elements (LEs)
■ Includes:
    – Error detection
    – False start bit detection
    – Automatic break detection
    – Internal and external sync character detection
■ Functionally based on the Intel M8251A device, except as noted in the  “Variations & Clarifications” on page 44