Serial Interface; Serial Connector - HP Compaq d330 DT Technical Reference Manual

Chapter 5 Input/Output Interfaces
5.4

SERIAL INTERFACE

Systems covered in this guide may include one RS-232-C type serial interface to transmit and
receive asynchronous serial data with external devices. Some systems may allow the installation
of a second serial interface. The serial interface function is provided by the LPC47B387 I/O
controller component that includes two NS16C550-compatible UARTs.
The UART supports the standard baud rates up through 115200, and also special high speed rates
of 239400 and 460800 baud. The baud rate of the UART is typically set to match the capability of
the connected device. While most baud rates may be set at runtime, baud rates 230400 and
460800 must be set during the configuration phase.

5.4.1 SERIAL CONNECTOR

The serial interface uses a DB-9 connector as shown in the following figure with the pinout listed
in Table 5-10.
Figure 5-4. Serial Interface Connector (Male DB-9 as viewed from rear of chassis)
Table 5-10. DB-9 Serial Connector Pinout
Pin Signal
1 CD
2 RX Data
3 TX Data
4 DTR
5 GND
The standard RS-232-C limitation of 50 feet (or less) of cable between the DTE (computer) and
DCE (modem) should be followed to minimize transmission errors. Higher baud rates may require
shorter cables.
5-10 hp compaq d330 and d530 Series of Personal Computers
Featuring the Intel Pentium 4 Processor
Table 5-10.
DB-9 Serial Connector Pinout
Description
Carrier Detect
Receive Data
Transmit Data
Data Terminal Ready
Ground
First Edition – June 2003
Pin Signal
6 DSR
7 RTS
8 CTS
9 RI
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Description
Data Set Ready
Request To Send
Clear To Send
Ring Indicator
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