Kontron KTT20-pITX - Manual (Page 25)

KTD-S0044-G Page 21 Serial Interface
KTT20/pITX User's Guide
10 Serial Interface
Three serial ports provide asynchronous serial communication with RS-232 interfaces. They are 16450/
16550 UART compatible and support 16-byte FIFO buffers for transfer rates from 50 Baud to 115.2 kBaud.
Following the connector assignment:
J2200 x UARTA/UART1
J2201 x UARTB/UART2
J2202 x UARTC/UART3
10.1 Connector
The serial ports are available through the connectors J2200, J2201 and J2202 (5 pins).
Header Pin Signal Description Type
1 TXD Transmit serial data O
2 RXD Receive serial data I
3 RTS# Request to send O
4 CTS# Clear to send I
5 GND Ground (shield) PWR
10.2 Serial Console
Most operating systems have a defined serial console. The KTT20/pITX uses the third serial port (UARTC/
UART3) on connector J2202 for this purpose. Normally the serial console needs only three signal lines
(TXD, RXD and GND). The serial port is assigned to the environment variables
stdin, stdout and stderr. If
you use U-Boot as bootloader you can interact with U-Boot via a USB keyboard and a standard terminal
program on a desktop computer. The following overview shows the default serial settings:
S
Baudrate 115 kBaud
S
Data bits 8
S
Stop bits 1
S
Parity No