User manual

Detailed hardware description

Issue E 47

Ethernet

The ZEUS SBC provides two 10/100-BaseTX interfaces with MAC and complies with

both the IEEE802.3u 10/100-BaseTX and the IEEE 802.3x full-duplex flow control

specifications.

Two single 10/100-BaseTX Ethernet controllers, Davicom DM9000A, are used to

implement Ethernet interfaces on ZEUS. DM9000A device provides an embedded PHY

and MAC and connects to 10/100-BaseTX magnetics. DM9000A also supports AUTO-

MDIX feature. Configuration data and MAC information are stored in an external serial

EEPROM (93LC46).

The DM9000A devices are connected to the PXA270 data bus (16-bit), and are memory

mapped. Connection to the ZEUS Ethernet ports is via dual RJ45 connector, J6, with

speed and link/activity status LEDs. For pin assignment and connector details, see J6 –

Ethernet connector

, page 72.

The link/activity LED (yellow) is illuminated when a 10/100-BaseTX link is made, and

when there is Tx/Rx activity. The speed LED (green) is illuminated when 100MB/s speed

is selected.

Serial COM ports

There are seven serial communications ports available on the ZEUS. Three are provided

by the PXA270 and are used for the optional wireless modem, GPS and IEEE802.15.4 /

ZigBee ports.

There are four additional high-speed, 16550 compatible serial UARTs implemented by an

EXAR ST16C554Q Quad UART device. Two of these channels (COM1, COM2) can be

used as standard RS232 serial interfaces, COM3 can be configured as RS232 or

RS485/422, and COM4 can be configured as RS422 or RS485. The table below provides

a summary of the four additional serial ports.

Port Address IRQ

FIFO depth

RX / TX Signals

COM1 0x10000000 –

0x1000000F

GPIO9 16/16 RS232: Rx, Tx, CTS, RTS, RI, DSR,

DCD, DTR

COM2 0x10800000 –

0x1080000F

GPIO10 16/16 RS232: Rx, Tx, CTS, RTS, RI, DSR,

DCD, DTR

COM3 0x11000000 –

0x1100000F

GPIO12 16/16 RS232: Rx, Tx, CTS, RTS, RI, DSR,

DCD, DTR

RS422/485: Rx, Tx

COM4 0x11800010 –

0x1180001F

GPIO11 16/16 RS422/RS485: Rx, Tx