UART参考设计，带16byte缓冲 VHDL代码 xapp223These small UART transmitter and receiver macros of just 7 and 8 Virtex CLBs respectivelyprovides all the functionality of a standard UART together with internal 16-byte FIFObuffers.UART_TX and UART_RX version 1.00 UART Receiver with internal 16-byte buffer and UART Transmitter with internal 16-byte buffer for Virtex, Virtex-E and Spartan-II