Compaq 850 manual Serial Interface Programming, Serial Interface Configuration

Technical Reference Guide

5.4.2 SERIAL INTERFACE PROGRAMMING

Programming the serial interfaces consists of configuration, which occurs during POST, and control, which occurs during runtime.

5.4.2.1 Serial Interface Configuration

The serial interface must be configured for a specific address range (COM1, COM2, etc.) and also must be activated before it can be used. Address selection and activation of the serial interface are affected through the PnP configuration registers of the LPC47B357 I/O controller.

The serial interface configuration registers are listed in the following table:

Table 5–8. Serial Interface Configuration Registers

	Table 5-8.
	Serial Interface Configuration Registers
Index
Address	Function	R/W
30h	Activate	R/W
60h	Base Address MSB	R/W
61h	Base Address LSB	R/W
70h	Interrupt Select	R/W
F0h	Mode Register	R/W

NOTE:

Refer to LPC47B357 data sheet for detailed register information.

Compaq Deskpro EXS and Workstation 300 Personal Computers 5-9

Featuring the Intel Pentium 4 Processor

First Edition - December 2000