Serial coms ports, Five serial ports jumpers, Three serial ports 10/10 – Eurotech Appliances VIPER / VIPER-LITE PXA255 User Manual

Page 64: Rminal, 323h, 324h

VIPER Technical Manual

Detailed hardware description

Serial COMs ports

There are five high-speed, fully functionally compatible 16550 serial UARTs on the
VIPER. Four of these channels can be used as standard RS232 serial interfaces, and
the remaining one (COM5) can be configured as RS422 or RS485.

Port Address

IRQ

FIFO depth
RX / TX

Signals

COM1 0x40100000 –

0x40100023

Internal

64 / 64

RS232 Rx, Tx, CTS, RTS, RI, DSR,

DCD, DTR

COM2 0x40200000 –

0x40200023

Internal

64 / 64

RS232 Rx, Tx, RTS, CTS

COM3 0x40700000 –

0x40700023

Internal

64 / 64

RS232 Rx, Tx

COM4 0x14300010 –

0x1430001F

GPIO4

128 / 128 RS232 Rx, Tx, CTS, RTS, RI, DSR,

DCD, DTR

COM5 0x14300000 –

0x1430000F

GPIO3

128 / 128 RS422 / RS485 Tx, Rx

Please see the PXA255 Developer’s Manual for details of internal interrupts.

COM1 – RS232 interface

Uses the full function UART in the PXA255 (FFUART). The port is buffered to RS232
levels with ±15kV ESD protection, and supports full handshaking and modem control
signals. The maximum baud rate on this channel is 230.4kb/s (CPU max capability). A
factory fit option configures COM1 as TTL Level signals to interface to a modem.
Please contact Eurotech Ltd for details. Contact details are provided in

COM2 – RS232 interface

Uses the Bluetooth UART in the PXA255 (BTUART). The port is buffered to RS232
levels with ±15kV ESD protection, and supports full handshaking and modem control
signals. The maximum baud rate on this channel is 921.6kb/s (CPU max capability).

COM3 – RS232 interface

Uses the Standard UART in the PXA255 (STUART). The port is buffered to RS232
levels with ±15kV ESD protection, and supports full handshaking and modem control
signals. The maximum baud rate on this channel is 230.4kb/s (CPU max capability).