Serial I/O (Sio) Port Functional Overview - Intel 8XC196K Series User Manual

Table of Contents

A serial input/output (SIO) port provides a means for the system to communicate with external

devices. This device has a serial I/O (SIO) port that shares pins with port 2. This chapter describes

the SIO port and explains how to configure it. Chapter 6, "I/O Ports," explains how to configure

the port pins for their special functions. Refer to Appendix B for details about the signals dis-

cussed in this chapter.

SERIAL I/O (SIO) PORT FUNCTIONAL OVERVIEW

The serial I/O port (Figure 7-1) is an asynchronous/synchronous port that includes a universal

asynchronous receiver and transmitter (UART). The UART has one synchronous mode (mode 0)

and three asynchronous modes (modes 1, 2, and 3) for both transmission and reception.

The T1CLK clock source is unique to the 8XC196K x .

For the 8XC196CA and J x , XTAL1 must provide the clock signal.

The serial port receives data into the receive buffer; it transmits data from the port through the

transmit buffer. The transmit and receive buffers are separate registers, permitting simultaneous

reads and writes to both. The transmitter and receiver are buffered to support continuous trans-

missions and to allow reception of a second byte before the first byte has been read.

Receive Shift Register

Transmit Shift Register

Control Logic

Figure 7-1. SIO Block Diagram

SERIAL I/O (SIO) PORT