Serial Port Interface Connectors: Cn21 (Com1), Cn14 (Com2) - AXIOMTEK EP820 Series User Manual

EP820 All-In-One EPIC Board User's Manual
CN23: 7-pin SATA connector
2.4.13 Serial Port Interface Connectors: CN21 (COM1),
CN14 (COM2)
The board has two onboard serial ports COM1 RS-232/422/485 and
COM2 RS-232 that can be jumper selectable with auto flow control
features. All ports are capable of +5V/12V power on DCD and RI,
depending on the jumper setting.
Serial Ports IRQ Selection
IRQ4 or IRQ3 are selected for IRQ of COM1 and COM2, both which
can be enabled or disabled via BIOS setting.
Serial Ports Power Selection
The two COM ports are capable of +5V power on DCD and of +12V
power for RI, depending on the jumper setting. The RS-232 pin
assignments are listed on the following table.
COM1 Port Connector Pin Assignment: CN21
Pin Description
1 DCD, Data Carrier Detect
2 RXD, Receive Data
3 TXD, Transmit Data
4 DTR, Data Terminal Ready
5 GND, Ground
6 DSR, Data Set Ready
7 RTS, Request To Send
8 CTS, Clear To Send
9 RI, Ring Indicator
28
Pin Description
1 GND
2 TX+
3 TX-
4 GND
5 RX-
6 RX+
7 GND
Jumpers and Connectors
CN21