12.1
Overview
The UART module is 16550 compatible. This module performs the serial to parallel conversion on
received data, and parallel to serial conversion on transmitted data. Individually, they contain a
programmable baud rate generator that is capable of dividing the input clock by a number from 1
to 65535; the data rate of each can also be programmed from 115.2K baud down to 50 baud. The c
haracter options are programmable for 1 start bit; 1, 1.5, or 2 stop bits; even, odd, stick or no
parity; and privileged interrupts. The HD64465 provides two UART ports.
12.2
Features
• Programmable FIFO or character mode
• In FIFO mode 16-byte FIFO buffer on the transmitter and receiver
• Add or delete standard asynchronous communication bits (start, stop, parity) to or from serial
data.
• The programmable Baud rate generator allows the division of input clock by 1 to 2
generates internal 16X clock
• MODEM control function (CTS#, RTS#, DTR#, DSR#, RI#, DCD#)
• Fully programmable serial-interface characteristics:
• 5, 6, 7 or 8 bit characters
• Even, odd, forced 0/1 or no parity bit generation and detection
• 1 ½, or 2 stop bit generation
• Baud rate generation (Dc to 115.2K baud)
• False start bit detection
• Two UART ports are provided (UART0 and UART1)
Section 12 UART
16
Rev. 3.0, 03/01, page 157 of 390
-1 and