Technical Reference Guide
Compaq Deskpro EXS and Workstation 300 Personal Computers
Featuring the Intel Pentium 4 Processor
First Edition - December 2000
5-9
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.
